Process for producing highly reactive modified phenolic resin and molding material

ABSTRACT

Disclosed is a process for producing a highly reactive modified phenolic resin, which comprises mixing a heavy oil or pitch with 0.3 to 10 mol of a phenol, 0.2 to 9 mol in terms of formaldehyde, of a formaldehyde compound and 0.01 to 3.0 mol of an acid catalyst, each amount being based on 1 mol of the heavy oil or pitch calculated from an average molecular weight; and heating the resulting mixture with stirring, thereby to polycondensate the heavy oil or pitch, phenol and formaldehyde compound. According to this invention, there can be provided a process for producing simply and stably a highly reactive modified phenolic resin having low melt viscosity, excellent heat resistance and high reactivity with an epoxy resin, in one step.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a process for producing a highlyreactive modified phenolic resin, which can simply produce a highlyreactive modified phenolic resin having low viscosity in one step, saidhighly reactive modified phenolic resin in combination with an epoxyresin being capable of providing a molded article excellent in heatresistance, moisture resistance, corrosion resistance, adhesion andmechanical characteristics (e.g. dimensional stability, strength, etc.),particularly in moisture resistance and heat resistance, and which canuse a polycondensation raw material capable of being stably fed andadvantageous in view of the cost.

The present invention also relates to a modified phenolic resin moldingmaterial, a material for electrical/electronic parts and a semiconductorsealing material, which contain the highly reactive modified phenolicresin obtained by this process, and an epoxy resin.

TECHNICAL BACKGROUND OF THE INVENTION

Phenolic resin molded articles have widely been used alone or incombination with other resins such as epoxy resin, etc. for a long timebecause of excellent mechanical characteristics, but had a problem thatthe light-resistance and alkali resistance are slightly low, thedimension and electric resistance are liable to change by absorption ofwater or an alcohol, and the heat resistance (particularly oxidationresistance at high temperature) is inferior.

Therefore, as a method of solving such a problem, various modificationsof the phenolic resin have been studied. For example, there have beensuggested a lot of modified phenolic resins wherein the resistance todeterioration or oxidation due to light, chemical, etc. is improved bymodification using fats, oils, rosin or a neutral aromatic compound.

For example, Japanese Patent Laid-Open Publication No. 61(1986)-235413discloses that a phenolic resin having excellent heat resistance can beobtained by selecting a reaction component of a phenol modified aromatichydrocarbon resin. However, the phenolic resin obtained by this methodhad a drawback that the resin must be maintained at a high temperaturefor a long time when a molded article is produced by using the phenolicresin.

Japanese Patent Laid-Open Publication No. 2(1990)-27414 discloses that amodified phenolic resin useful for molding material, having excellentheat resistance, oxidation resistance and mechanical strength, as cannotbe expected from a conventional phenolic resin, is obtained by employingpetroleum heavy oils or pitches as a cheap raw material and selectingspecial reaction condition.

Further, Japanese Patent Laid-Open Publication No. 4(1992)-145116discloses that, in the production of such a phenolic resin, a crudemodified phenolic resin obtained by a polycondensation of startingcompounds is subjected to a neutralization treatment, a water washingtreatment and/or an extraction treatment to thereby neutralize andremove any acid remaining in the crude modified phenolic resin, so thata modified phenolic resin which does not corrode a metal member broughtinto contact with the resin is provided.

In the above process for producing the modified phenolic resin, the acidremaining in the crude modified phenolic resin is actually neutralizedand removed by the neutralization treatment using an amine, followed bythe water washing treatment. However, the modified phenolic resinobtained through the purification step involving the aboveneutralization and water washing treatments is likely to retain aneutralization product therein, so that there is a problem that it isunsatisfactory as a molding material used for a product on which strictrequirements for thermal and corrosion resistance are imposed, such as amolding material for electrical or electronic part and a material forsemiconductor sealer.

Japanese Patent Laid-Open Publication No. 6(1994)-228257 teaches that amodified phenolic resin containing substantially no acid can be obtainedby purifying a crude modified phenolic resin through a purification stepincluding a specific extraction treatment. The modified phenolic resincontaining substantially no acid, obtained through this purificationstep, may be combined with an epoxy resin, so that a molding materialcan be obtained, which not only has excellent thermal and moistureresistance but also does not corrode any metals.

However, the above modified phenolic resin has a drawback in that themelt viscosity of the resin is so high that the resin is not suitablefor speedy mass production of a molded article having a complexconfiguration. In addition, further improvements of thermal resistance,dimensional stability and strength and other mechanical properties havebeen demanded in the use of the modified phenolic resin in combinationwith an epoxy resin.

The present inventors proposed a process for producing a highly reactivemodified phenolic resin having a low resin melt viscosity and animproved reactivity with the epoxy resins by means of reacting amodified phenolic resin with a phenol in the presence of an acidcatalyst to thereby lower the molecular weight of the modified phenolicresin (See Japanese Patent Laid-Open Publication No. 7(1995)-252339 andJapanese Patent Application No. 8(1996)-24173).

The highly reactive modified phenolic resins obtained as described aboveare relatively low in viscosity and are capable of providing a moldingmaterial having good thermal resistance and moldability, as well assuperior mechanical strength such as dimensional stability when combinedwith an epoxy resin.

However, according to such a method of producing the modified phenolicresin, two steps of the polycondensation step and the molecular-weightlowering step are required and, therefore, the production step becamecomplicated.

By the way, in case of soldering which is generally performed onproduction of electrical appliances, electrical/electronic parts areexposed to high temperature. From this point of view, a furtherimprovement in heat resistance is requested to the modified phenolicresin used as a resin material for electrical/electronic parts orsemiconductor sealing material.

When the moisture absorption property of the resin material is high,there arises a problem that water is rapidly evaporated on soldering tocause a package crack and has a capability of corroding metal materialcombined with the resin.

The resin material is often used in combination with a metal member inthe field of the electrical/electronic parts or semiconductor sealingmaterial, and the reliability of the product is largely influenced bythe adhesion between the resin material and metal member.

Accordingly, a further improvement in moisture absorption and that inadhesion were also rquired to the modified phenolic resin.

In addition to the simplification of the production step and improvementin characteristics of the resulting modified phenolic resin as describedabove, it is also highly requested to use a raw oil which can beobtained more effectively and stably and is advantageous in view of thecost, in place of a raw oil obtained by redistilling a residual oilobtained in a conventional catalytic cracking step.

The present inventors have studied intensively about a method ofproducing a highly reactive modified phenolic resin having excellentcharacteristics described above more simply. As a result, it has beenfound that, by mixing specific raw materials (including a catalyst) in aspecific ratio to polycondense them, a highly reactive modified phenolicresin having high reactivity with the epoxy resin and low viscosity canbe obtained in one step.

The present inventors also have found that a molding material preparedby using this highly reactive modified phenolic resin in combinationwith an epoxy resin can provide a molded article which is excellent inheat resistance, moisture resistance, corrosion resistance, adhesion,and mechanical characteristics (e.g. dimensional stability, strength,etc.), particularly moisture resistance and heat resistance.

The present invention has been accomplished based on these findings ofthe present inventors.

OBJECTS OF THE INVENTION

The present invention has been accomplished to solve the above describedproblems of the prior art, and an object thereof is to provide a processfor producing a highly reactive modified phenolic resin which can simplyand stably produce and feed a highly reactive modified phenolic resinhaving low melt viscosity and high reactivity with an epoxy resin in onestep.

Another object of the present invention is to provide a moldingmaterial, particularly material for electrical/electronic parts andsemiconductor sealing material, comprising the highly reactive modifiedphenolic resin obtained by the above method, and an epoxy resin, whichcan produce a molded article which is excellent in heat resistance,moisture resistance, corrosion resistance, adhesion, and mechanicalcharacteristics (e.g. dimensional stability, strength, etc.),particularly moisture resistance and heat resistance.

SUMMARY OF THE INVENTION

The method of producing the highly reactive modified phenolic resinaccording to the present invention comprises mixing a heavy oil orpitch, a phenol, a formaldehyde compound and an acid catalyst in aspecific amount, and heating the resulting mixture with stirring,thereby to polycondensate the heavy oil or pitch, phenol andformaldehyde compound.

In the present invention, the polycondensation reaction may be performedby heating the mixture obtained by mixing all polycondensation rawmaterials (including the catalyst) with stirring (first process), or thepolycondensation may be performed by heating the mixture obtained bymixing specific ones selected from among the polycondensation rawmaterials (including the catalyst) with stirring, and polycondensingwhile adding gradually the remainder of the polycondensation rawmaterials (or catalyst) (second to sixth process).

In the first to sixth processes of producing the highly reactivemodified phenolic resin according to the present invention, a petroleum-or coal-based material, especially, a specific distilled oil obtained inthe catalytic cracking step or a thermal cracking step during thepetroleum refining process can be used as the heavy oil or pitch and,furthermore, an aromatic hydrocarbon compound can be also added as theraw material.

In the first to sixth processes of producing the highly reactivemodified phenolic resin according to the present invention, it isdesirable to use a Br.O slashed.nsted acid selected from the groupconsisting of organic acid, inorganic acid and solid acid as the aboveacid catalyst.

In the first to sixth processes of producing the highly reactivemodified phenolic resin according to the present invention, the heavyoil or pitch may be used after subjecting to a treatment of removing aparaffin fraction as a low-reactive component.

In the production process of the present invention, it is preferable topurify the highly reactive modified phenolic resin obtained by the abovepolycondensation reaction, by at least one step selected from the groupconsisting of:

(i) a step of removing an unreacted component from the reaction mixture,

(ii) a step of removing a catalyst residue, and

(iii) a step of removing the remained phenol, and to use the resultingpurified highly reactive modified phenolic resin in various purposes.

The modified phenolic resin molding material of the present inventioncomprises the highly reactive modified phenolic resin obtained by theabove process and an epoxy resin. This modified phenolic resin moldingmaterial may further contain an inorganic filler, in addition to theseresin components.

The electrical/electronic parts of the present invention are obtained bymolding the highly reactive modified phenolic resin molding material.

Furthermore, the semiconductor sealing material of the present inventionis composed of the highly reactive modified phenolic resin moldingmaterial.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be described in detail hereinafter.

In the process for producing the highly reactive modified phenolic resinaccording to the present invention, the highly reactive modifiedphenolic resin is produced by heating a mixture containing a specificamount of heavy oil or pitch, a formaldehyde compound, a phenol and anacid catalyst with stirring, thereby to perform the polycondensationreaction.

As the heavy oil or pitch used for the raw material of thepolycondensation reaction in the present invention, any of petroleum-and coal-based raw oils may be used. Examples of the petroleum heavy oilor pitch include distilled residual oil, hydrogenolysis residual oil andcatalytic cracking residual oil of crude oil; thermal cracking residualoil of naphtha or LPG; vacuum distillate of these residual oils; extractby solvent extraction or heat-treated product; and specific distilledoil obtained by cracking steps during the petroleum refining processsuch as thermal cracking, catalytic cracking, etc. Examples of the coalheavy oils or pitches include specific fractional component obtained bydistilling coal tar in coal dry distillation, and heavy oil in coalliquefaction.

It is preferable that those having suitable aromatic hydrocarbonfraction fa value and aromatic ring hydrogen content Ha value beselected from the petroleum heavy oils or pitches and used.

The petroleum heavy oils or pitches desirably have a fa value of 0.40 to0.95, preferably 0.5 to 0.8, more preferably 0.55 to 0.75, and a Havalue of 20 to 80%, preferably 25 to 60%, more preferably 25 to 50%.

The fa value and Ha value are calculated from data by measurements of ¹³C-NMR and ¹ H-NMR of petroleum heavy oils or pitches according to thefollowing equations, respectively. ##EQU1##

When the fa value of the petroleum heavy oil or pitch as a raw materialis smaller than 0.4, the aromatic content is low, so that it is likelythat the effect thereof on the improvement of the performance, such asthermal and oxidation resistance, of the resultant modified phenolicresin is less.

On the other hand, when the petroleum heavy oil or pitch has an fa valueof greater than 0.95, the reactivity of carbons of aromatic rings withformaldehyde is likely to become unfavorably low.

When the Ha value of the petroleum heavy oil or pitch as a raw materialis smaller than 20%, the amount of aromatic ring hydrogen atoms reactingwith formaldehyde is less to thereby cause the reactivity lowering, sothat the effect thereof on the improvement of the performance of thephenolic resin is likely to become poor.

On the other hand, when a petroleum heavy oil or pitch having an Havalue of greater than 80% is used as a raw material, the strength of themodified phenolic resin is likely to become poor.

It is particularly preferable to use a distilled oil obtained incracking steps such as thermal cracking and catalytic cracking in thepetroleum refining process as the petroleum heavy oils or pitches inview of stable feed of the raw material, elimination of a pretreatment,etc.

In the petroleum refining process, examples of the raw material used inthe cracking step include tar sand, and residual oil, refined oil andintermediate refined oil, for example, oils obtained in distillationstep, such as straight-run heavy gas oil, topped crude oil and vacuumdistillation residual oil; and oils obtained in the desulfurizationstep, such as desulfurized vacuum heavy gas oil and desulfurized heavyoil. Among these residual oils, refined oils and intermediate refinedoils, tar sand, topped crude oil and vacuum distilled residual oil arenormally used in the thermal cracking, and straight-run heavy gas oil,topped crude oil, desulfurized vacuum heavy gas oil and desulfurizedheavy oil are normally used in the catalytic cracking.

The catalytic cracking method and thermal cracking method applied in theproduction of the distilled oil may be any method capable of obtaining adistilled oil having the above desired characteristics and notspecifically limited. That is, any catalytic cracking method or thermalcracking method, which has hitherto been applied in the field of thepetroleum purification, can be used. Accordingly, examples of thecatalytic cracking method include moving bed catalytic cracking method,air-lift thermophore catalytic cracking method, Houdriflow catalyticcracking method, fluidized bed catalytic cracking (FCC) method, UOPfluid catalytic cracking method, Shell 2-stage fluid catalytic crackingmethod, ER & E Model IV catalytic cracking method, Orthoflow catalyticcracking method and the like. Examples of the thermal cracking methodinclude delayed coking method, fluid coking method, Flexicoking method,bisbreaking method, EUREKA method, CHERY-P method, ACTIV method, KKImethod, Coke fluidized bed coking method, ACR and the like.

In the cracking step, the catalytically cracked product and thermallycracked product thus obtained by these methods are separated intofractions having various true boiling points and various compoundcompositions. Among them, the distilled oil used preferably in thepresent invention has the above aromatic hydrocarbon fraction fa valueand aromatic ring hydrogen content Ha value and has a true boiling pointof 180 to 500° C., preferably of 180 to 490° C., more preferably of 190to 490° C.

When a distilled oil having a true boiling point of less than 180° C. isused, the amount of the condensed polycyclic aromatic componentcontained in the raw oil is small and the reactivity is lowered.

Such a distilled oil is a comparatively heavy fraction drawn from thecolumn intermediate stage other than the column top and column bottom,among those distilled in the cracking step. Accordingly, by using thecolumn-intermediate distilled oil as the polycondensation raw material,it is possible to use, as a raw material, a fraction obtained by feedingfrom a reaction column to a distillation column, i.e. intermediaterefined oil and circulating oil in the catalytic cracking device and thethermal cracking device which have hitherto been used in the crackingstep of the petroleum refining process, and it is not necessary todistill a bottom oil again. Therefore, it becomes possible to feed theraw material in high stability and low cost.

The fractional component obtained by distillation of coal tar, describedas the coal raw material, is a fractional component having a boilingpoint of higher than 200° C., preferably 200 to 360° C.

The coal dry distillation is an essential step in the coal chemicalindustry, and is performed to produce a gas, coal tar and coke fromcoal.

The coal tar produced by the coal dry distillation is classified intocoal oven tar, horizontal retort tar, vertical retort tar, producer tar,aqueous gas tar, etc. corresponding to the dry distillation system.

The coal tar is classified into high-temperature tar (900 to 1200° C.)and low-temperature tar (450 to 700° C.) corresponding to the drydistillation temperature, and they differ in composition and properties.

In the present invention, the fractional component used as the coalheavy oil or pitch may be any of those obtained by distilling any coalso long as the fractional component has the above boiling point, buthigh-temperature coal such as coke oven tar is particularly preferablefor the method of the fractional component in view of large content ofthe desired distilled component.

When these coal tars are distilled, various fractional components can beobtained. For example, when the coak oven tar obtained in the productionof coak is distilled, tar gas oil (boiling point: about 94 to 178° C.),carbol gas oil (carbolic oil: boiling point of about 168 to 200° C.),naphthalene oil (middle oil) and absorbing oil (boiling point: about 202to 223° C.), heavy oil (boiling point: about 218 to 314° C.), anthraceneoil (boiling point: about 296 to 360° C.) and pitch (residue: boilingpoint of about 450° C. or more), etc. can be obtained as the fractionalcomponents.

Among them, the fractional component whose boiling point exceeds 200° C.include naphthalene oil, absorbing oil, heavy oil, anthracene oil andpitch.

As the coal heavy oil or pitch used in the present invention, thesefractional components having the above boiling point may be used aloneor in combination thereof. Those obtained by separating/recoveringspecific components from a mixture of these fractional components mayalso be used. For example, it is also possible to use a mixture of thefractions having a boiling point higher than that of naphthalene oil,such as creosote oil obtained by separating/recovering naphthalene,anthracene, tar acids, tar base, etc. and mixing them.

The coal heavy oil or pitch (coal tar) have a higher Fa and Ha valuesthan the petroleum-based materials, but the reaction thereof with theformaldehyde compound well undergoes. From the fact, it can be expectedthat the coal-based material may have an essential difference inreactivity with the formaldehyde compound from the petroleum-basedmaterial, based on its molecular structure.

When a fractional component having a boiling point of 200° C. or less isused, the amount of the condensed polycyclic aromatic componentcontained in the raw oil is small and the reactivity is lowered.

The coal liquefaction is performed to produce gasoline from coal, and isa process comprising reacting coal with high-pressure hydrogen (200 to700 atm) at high temperature of about 500° C. and subjecting theresulting product to various reactions such as coal structure cleavage,deoxygenation, desulfutrization, distillation hydrogenation, etc. toform a lower hydrocarbon.

In the present invention, as the coal heavy oil or pitch, such a heavyoil produced by the coal liquefaction can also be used, and this heavyoil may be used alone or in combination with one or more coal tarfraction components described above.

The coal heavy oils or pitches described above are products which arestably produced by the general step in the coal chemical industry.Accordingly, it becomes possible to feed the raw material in highstability and low cost by using them.

In the present invention, the coal heavy oils or pitches may be used asthey are, but there is a possibility to contain acidic compounds such asphenols, carboxylic acids, etc. and basic compounds such as carbazoles,pyridines, anilines, quinolines, etc. Therefore, these compounds arepreferably removed.

The removal of these acidic compounds and basic compounds can beperformed, for example, by extraction with sulfuric acid, sodiumhydroxide, and the like.

In the petroleum and coal heavy oils or pitches described above, thenumber of condensed rings constituting them is not specifically limited,but the petroleum and coal heavy oils or pitches are preferably composedmainly of condensed polycyclic aromatic hydrocarbons of 2 to 4 rings.When the heavy oils or pitches exclusively contain condensed polycyclicaromatic hydrocarbons of 5 or more rings, this condensed polycyclicaromatic hydrocarbon has generally high boiling point and the boilingpoint exceeds 450° C., sometimes. Therefore, a scatter in boiling pointof the raw material increases and it becomes difficult to collect thosehaving narrow boiling range, thereby making it difficult to stabilizethe quality of the product. Furthermore, when the heavy oils or pitchesare mainly composed of monocyclic aromatic hydrocarbons, the reactivitybetween them and formaldehyde is low so that the modification effect ofthe resulting phenolic resin is liable to become smaller.

These heavy oils or pitches may be used as they are in thepolycondensation reaction, but may also be used after subjecting to atreatment of removing a saturated hydrocarbon fraction having 15 to 40carbon atoms, which contains a low-reactive paraffin fraction, i.e.normal paraffin, isoparaffin, cycloparaffin, etc.

Such a treatment of removing the paraffin fraction can be performed, forexample, by column chromatography at 80 to 120° C. using furfuralaccording to a normal method.

Examples of a filler to be packed in the column used in columnchromatography include active alumina gel, silica gel and the like.These fillers can be used alone or in combination thereof.

Examples of a developer used in the chromatography include aliphaticsaturated hydrocarbon compounds having 5 to 8 carbon atoms, such asn-pentane, n-hexane, n-heptane and n-octane; ethers such as diethylether; halogenated hydrocarbons such as chloroform and carbontetrachloride; and alcohol such as methyl alcohol and ethyl alcohol.These developers are preferably used in combination thereof,appropriately.

By performing such a treatment of removing a paraffin fraction, not onlythe modification effect of the performances of the modified phenolicresin can be improved, but also the amount of the unreacted componentcan be reduced to facilitate the purification treatment.

Examples of the phenol used, together with the above heavy oils orpitches, as the raw material in the present invention includehydroxybenzene compound and hydroxynaphthalene compound. Examples of thehydroxybenzene compound include phenol, cresol, xylenol, resorcin,hydroquinone, catechol, phenyl phenol, vinyl phenol, nonyl phenol,p-tert-butyl phenol, bisphenol A, bisphenol F and the like. Examples ofthe hydroxynaphthalene compound include monohydroxynaphthalene compoundssuch as α-naphthol and β-naphthol; dihydroxynaphthalene compounds suchas 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene,1,4-dihydroxynaphthalene, 2,3-dihydroxynaphthane,3,6-dihydroxynaphthalene, 1,5-dihydroxynaphthalene,1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthane,2,6-dihydroxynaphthalene and 2,7-dihydroxynaphthane; and mono- ordihydroxynaphthalene compounds having a substituent (e.g. alkyl group,aromatic group, halogen atom, etc.), such as 2-methyl-1-naphthol,4-phenyl-1-naphthol, 1-bromo-2-naphthol and 6-bromo-2-naphthol. Thesephenols may be used alone or in combination thereof.

In the process of producing the highly reactive modified phenolic resinaccording to the present invention, it is desired that the phenol isused in an amount of 0.3 mol or more and 10 mol or less, preferably 9 orless, more preferably 8 or less, per mol of the heavy oil or pitchcalculated from the average molecular weight.

When the phenol is used in the amount of less than 0.3 mol, since thereactivity between the heavy oil or pitch and formaldehyde is inferiorto that between the phenol and formaldehyde, sufficient crosslinkdensity may become not obtained and the strength of the cured articlemay become smaller than that of a general phenolic resin. Particularly,the cured articles are liable to show a drawback such as low impactresistance and brittleness. On the other hand, when the amount of thephenol exceeds 10 mol, the modification effect as a result of themodification of the phenolic resin is liable to decrease.

The aromatic hydrocarbon compound used in the polycondensation reactionof the present invention is an aromatic hydrocarbon compound composedonly of a hydrocarbon group and an aromatic ring or a halogenatedproduct thereof, and it has an effect of improving the moistureabsorption-resistant property and adhesion of the resin.

In the aromatic hydrocarbon compound used in the present invention, thearomatic ring may be a single ring or a condensed ring, and the same ordifferent two or more aromatic rings may be combined by a bond or ahydrocarbon bonding group.

Examples of the hydrocarbon group as a substituent of the aromatic ringinclude alkyl groups such as methyl group, ethyl group and the like.

Examples of the halogen atom contained in the halogenated aromatichydrocarbon compound include fluorine, chlorine, bromine, iodine and thelike.

Examples of the aromatic hydrocarbon compound include compounds having anon-condensed aromatic ring, for example, alkyl group-substitutedbenzene compounds such as toluene, o-xylene, m-xylene, p-xylene, etc.;and halogenated benzene compounds (which may be substituted with analkyl substituent) such as chlorobenzene, o-chlorotoluene,m-chlorotoluene, p-chlorotoluene, etc.

In the first to sixth processes of producing the highly reactivemodified phenolic resin according to the present invention, the aromatichydrocarbon compound is desirably used in an amount of 0.1 to 5 mol,preferably 0.5 to 3 mol, more preferably 0.5 to 2 mol, per mol of theheavy oils or pitches calculated from the average molecular weight.

When the aromatic hydrocarbon compound is used in an amount of less than0.1 mol, the desired improving effect of the moisture absorptionproperty and adhesion may not be obtained. On the other hand, when theamount of the aromatic hydrocarbon compound exceeds 5 mol, the desiredimproving effect of the heat resistance may not be obtained.

Examples of the formaldehyde compound used in the polycondensationreaction of the present invention include linear polymers such asparaformaldehyde and polyoxyethylene (particularly oligomer); and cyclicpolymers such as trioxane, in addition to formaldehyde.

Such a formaldehyde compound serves as a crosslinking agent, andparaformaldehyde and formaldehyde are particularly preferable. Theformaldehyde compound may be used after dissolving in a suitable solventsuch as water, etc. Accordingly, formaldehyde may be used as an aqueoussolution having a suitable concentration, and it is particularlypreferable to use it as formalin (concentration: 35% or more).

In the method of producing the highly reactive modified phenolic resinaccording to the present invention, such a formaldehyde compound isdesirably used in an amount of 0.2 or more, preferably 0.5 or more, and9 mol or less, preferably 7 mol or less, more preferably 6 mol or lessin terms of formaldehyde, per mol of the heavy oil or pitch calculatedfrom the average molecular weight.

When the amount of the formaldehyde compound per mol of the heavy oil orpitch is less than 0.2 mol, the resin yield is lowered and the strengthof the resulting modified phenolic resin is unfavorably low. On theother hand, when the amount of the formaldehyde compound is larger than9 mol, not only the resulting modified phenolic resin becomes to have sohigh moleclar weight that the desired viscosity is not obtained, butalso the reaction mixture is sometimes solidified.

In the second to sixth methods of producing the phenolic resin accordingto the present invention, the formaldehyde compound is used in theamount of 1 mol or less, preferably 0.9 mol or less, more preferably 0.8mol or less, in terms of formaldehyde, per mol of the phenol.

When the amount of the formaldehyde compound per mol of the phenolexceeds 1 mol, not only the resulting modified phenolic resin becomes tohave so high molecular weight that the desired viscosity is notobtained, but also the reaction mixture is sometimes solidified.

In the polycondensation reaction according to the present invention, anacid catalyst is used to polycondensate the heavy oils or pitches,formaldehyde compound and phenols. As such an acid catalyst, a Br.oslashed.nsted acid or a Lewis acid can be used, but a Br.o slashed.nstedacid is preferably used. Examples of the Br.o slashed.nsted acid includeorganic acids such as oxalic acid, toluenesulfonic acid, xylenesulfonicacid and formic acid; inorganic acids such as hydrochloric acid andsulfuric acid; and solid acids such as acidic cation exchange resin.

Among these Br.o slashed.nstead acids, oxalic acid and sulfuric acid arepreferable as the organic acid and inorganic acid, respectively.

The acidic cation exchange resin used as the solid acid is a resinobtained by covalent-bonding a base resin having a three-dimensionalnetwork with a cation exchange group.

Examples of the base resin include polystyrene, styrene/divinylbenzenecopolymer, poly(meth)acrylic acid and polyacrylonitrile. Examples of thecation exchange group include strong-acidic groups such as sulfonategroup; and weak-acidic groups such as carboxyl group.

The acidic cation exchange resin as the acid catalyst is desirably usedas a spherical substance having a normal particle size of 15 to 50 mesh.

Specific examples of the acidic cation exchange resin includestrong-acidic cation exchange resins such as Daiya-ion SKIB, PK216,SH104 and PK208 (trade name, manufactured by Mitsubishi Chemical Co.,Ltd.), Amberlite IR-120B and IR-112 (trade name, manufactured by OrganoCo.), Dowex 50wx 8, HCR and HGR (trade name, manufactured by DowChemical Co.), and Duolite C-20 and C-25 (trade name, manufactured bySumitomo Chemical Industries Co., Ltd.); and weak-acidic cation exchangeresins such as Daiya-ion WK10 (trade name, manufactured by MitsubishiChemical Co., Ltd.), Amberlite IRc-50 (trade name, manufactured byOrgano Co.) and Duolite CS-101 (trade name, manufactured by SumitomoChemical Industries Co., Ltd.).

When such a solid acid is used as the acid catalyst, an acid is notcontained in the reaction mixture at the free state. Therefore, there isan advantage that a low-density highly reactive modified phenolic resincontaining substantially no acid can be obtained by removing the solidacid from the polycondensation reaction product by a simple method suchas filtration.

In the first process according to the present invention, the acidcatalyst is used in an amount of 0.01 mol or more, preferably 0.05 molor more, and 3 mol or less, preferably 2 mol or less, per mol of theheavy oil or pitch calculated from the average molecular weight. In thesecond to sixth processes according to the present invention, the acidcatalyst is desirably used in an amount of 0.01 mol or more, and 3 molor less, preferably 2.5 mol or less, more preferably 2 mol or less, permol of the heavy oil or pitch calculated from the average molecularweight. When the acidic cation exchange resin is used as the acidcatalyst, the amount of the above acid catalyst is a value in terms of acation exchange group.

When the amount of the acid catalyst is small, the reaction time isliable to increase and, if the reaction temperature is not high, thereaction is liable to be insufficient. On the other hand, even if theamount of the acid catalyst is increased, the reaction rate does notincrease and it may become disadvantageous in view of the cost.

In the first process for producing the highly reactive modified phenolicresin according to the present invention, a specific amount of theabove-described raw materials and acid catalyst are previously mixed andthen the resulting mixture is polycondensed by heating with stirring.

In the polycondensation reaction of the heavy oil or pitch, phenol andformaldehyde compound in the presence of the acid catalyst, the rawmaterial mixing temperature, mixing time, polycondensation temperatureand reaction time are controlled according to the raw materialcomposition and properties of the resulting resin. As a matter ofcourse, the reaction temperature and reaction time are conditions whichinteract each other.

Such a polycondensation reaction can be performed, for example, by thefollowing method.

First, the specific amount of the above heavy oil or pitch, phenol,formaldehyde and acid catalyst are uniformly mixed by stirring at thetemperature where no polycondensation proceeds, e.g. 50° C. or less,preferably 40 to 50° C.

Then, the resulting mixture is slowly heated to the temperature of 50 to200° C., preferably 80 to 200° C., more preferably 80 to 180° C., andthe polycondensation reaction is performed for 15 minutes to 8 hours,preferably 30 minutes to 6 hours.

Mixing of the polymerization raw materials is performed so that anuniform mixture is obtained before the polycondensation reactionproceeds, and may be performed while slowly elevating the temperature tothe polycondensation reaction temperature.

In the second to sixth processe of producing the highly reactivemodified phenolic resin according to the present invention, at least oneof the heavy oil or pitch, acid catalyst and formaldehyde compound isgradually or successively added in the polycondensation reaction usingthe above-described raw materials and acid catalyst.

That is, in the second process for producing the highly reactivemodified phenolic resin, first, the heavy oil or pitch and phenol aremixed and heated with stirring, and then the formaldehyde compound andacid catalyst are gradually added to this mixture during heating withstirring. In this process, the acid catalyst and total amount of theformaldehyde may be gradually added. On the other hand, when a part ofthe formaldehyde compound has been mixed in the mixture to be heatedwith stirring, the remainder of the formaldehyde compound is graduallyadded, together with the acid catalyst.

In the third process for producing the highly reactive modified phenolicresin according to the present invention, first, the heavy oil or pitch,phenol and formaldehyde compound are mixed and heated with stirring, andthen only the acid catalyst is gradually added to this mixture duringheating with stirring.

In the fourth process for producing the highly reactive modifiedphenolic resin according to the present invention, first, the petroleumheavy oil or pitch, phenol and acid catalyst are mixed and heated withstirring, and then only the formaldehyde compound is gradually added tothis mixture during heating with stirring.

In the fifth process for producing the highly reactive modified phenolicresin according to the present invention, first, the heavy oil or pitch,phenol and acid catalyst are mixed and heated with stirring, and thenthe phenol and formaldehyde compound are gradually added to this mixtureduring heating with stirring.

In the sixth process for producing the highly reactive modified phenolicresin according to the present invention, first, the formaldehydecompound and acid catalyst are mixed and heated with stirring, and thenthe heavy oil or pitch and phenol are gradually added to this mixtureduring heating with stirring.

In the second to sixth processes of producing the highly reactivemodified phenolic resin according to the present invention, the gradualaddition of the heavy oils or pitches, acid catalyst and/or formaldehydecompound is desirably performed over 10 to 120 minutes, preferably 20 to80 minutes, by using a method such as dropwise addition, etc.

When the addition time is less than 10 minutes, the reaction may rapidlyproceed to cause drastic heat generation and it unfavorably becomesdifficult to control the temperature. On the other hand, when theaddition time exceeds 120 minutes, it takes a long time to the additionand the reaction times is liable to become longer.

In the polycondensation reaction according to the present invention, thegradual addition to the mixture during heating with stirring is notspecifically limited in its initiation time and may be started in thestate where the mixture during heating with stirring is uniformly mixedand the temperature is stable.

In the second process for producing the modified phenolic resinaccording to the present invention, the formaldehyde compound isgradually added together with the acid catalyst, but this gradualaddition of the formaldehyde compound may be started or terminatedsimultaneously with the gradual addition of the acid catalyst. In thiscase, both are desirably mixed. The gradual addition of the formaldehydecompound may be performed separately with the addition of the acidcatalyst. In this case, the addition of the formaldehyde compound may beperformed simultaneously with the addition of the acid catalyst, or maybe started before the addition of the acid catalyst.

In the polycondensation reaction of the heavy oil or pitch, phenol andformaldehyde compound in the presence of the acid catalyst, wherein theraw materials and acid catalyst are added in such an order, the reactiontemperature and reaction time are controlled according to the rawmaterial composition, addition rate of the acid catalyst, properties ofthe resulting resin, etc. As a matter of course, the reactiontemperature and reaction time are conditions which interact each other.

In the second to fourth processes of producing the highly reactivemodified phenolic resin according to the present invention, such apolycondensation reaction can be performed, for example, by thefollowing method.

First, the raw material containing the heavy oils or pitches and phenolsand, if necessary, at least a part of the formaldehyde compound or acidcatalyst is uniformly mixed by heating with stirring at the temperatureof 30 to 120° C., preferably 40 to 80° C., before the addition of theformaldehyde compound and/or acid catalyst.

Then, the formaldehyde compound and/or acid catalyst are gradually addedwhile paying attention to a rapid increase in temperature of thereaction mixture.

After the completion of the addition of the formaldehyde compound and/oracid catalyst, the reaction mixture is heated to the temperature of 50to 200° C., preferably 80 to 200° C., more preferably 80 to 180° C., andthe reaction is performed for 15 minutes to 8 hours, preferably 30minutes to 6 hours. The fifth and sixth processes can be carried outunder the same conditions.

In the first to sixth processes according to the present invention, thepolycondensation reaction of the heavy oil or pitch, formaldehydecompound and phenol can be performed without using a solvent, but theviscosity of the reaction mixture (reaction system) may be reduced byusing a suitable solvent to make an uniform reaction performed.

Examples of such a solvent include nitrated aromatic hydrocarbons suchas nitrobenzene; nitrated aliphatic hydrocarbons such as nitroethane andnitropropane; and haloganated aliphatic hydrocarbons such as Perchlene,Trichlene and carbon tetrachloride.

Regarding the above-described processes of producing the highly reactivemodified phenolic resin according to the present invention, a molecularweight lowering step is not required and the number of steps is markedlyreduced in comparison with the process for producing the highly reactivemodified phenolic resin disclosed in Japanese Patent Laid-openPublication No. 7(1995)-252339.

The highly reactive modified phenolic resin of the present invention isexcellent in moldability because of its low resin melt viscosity, and isexcellent in heat resistance to the highly reactive modified phenolicresin disclosed in Japanese Patent Laid-Open Publication No.7(1995)-252339. Furthermore, the highly reactive modified phenolic resinof the present invention has excellent adhesion and low moistureabsorption property when the aromatic hydrocarbon compounds is containedas the raw material. Since the highly reactive modified phenolic resinof the present invention has these characteristics, it is possible toprovide a modified phenolic resin molding material which is superior inmechanical characteristics (e.g. dimensional stability, strength, etc.),moisture resistance and heat resistance and shows excellent adhesion andlow moisture absorption property by using in combination with an epoxyresin.

The highly reactive modified phenolic resin thus produced can be appliedto various purposes, but there is a possibility that the unreactedcomponent and acid catalyst are remained in the resin. Therefore, it ispreferable that the unreacted component, low molecular component, acidcatalyst and reaction solvent be removed by subjecting it to apurification treatment, appropriately.

Examples of the process of purifying the reaction mixture, i.e., thecrude highly reactive modified phenolic resin containing the acidcatalyst, low molecular component and reaction solvent include (i)purification treatment of removing the unreacted component from thereaction mixture, (ii) purification treatment of removing the catalystresidue from the reaction mixture, and (iii) purification treatment ofremoving the remaining phenols by any one of steam distillation, blowingof a nitrogen gas and vacuum distillation.

In the above purification treatment (i), among the components containedin the heavy oil or pitch used as the raw material, the componentremained in the reaction product in the unreacted state or the state ofinsufficient reaction, and the reaction solvent used in the reaction areremoved.

In the first treatment of removing the unreacted component from thereaction mixture, the polycondensation reaction obtained by the first tosixth polycondensation processes is brought into contact with a specificextraction solvent at the temperature where this reaction mixture iscapable of keeping a flow state, thereby to remove the unreactedsubstance contained in the reaction mixture, e.g. low-reactive substancecontained in the heavy oils or pitches and a low molecular weightcomponent remained in the state of insufficient reaction.

The temperature where the reaction mixture is capable of keeping a flowstate is a temperature where the reaction mixture can maintain a liquidstate to form a liquid-liquid two-phase with the extraction solvent, ora temperature where the reaction mixture can maintain a flow state bybeing dissolved in the extraction solvent. The rate and efficiency ofextraction of the unreacted substance, contained in the reactionmixture, into the extraction solvent can be increased by heating thereaction mixture to the temperature where the reaction mixture canmaintain the flow state and bringing it into contact with the extractionsolvent.

The extraction solvent used in this first treatment is a solvent whichforms a liquid-liquid two-phase system or a solution with the reactionmixture containing the modified phenolic resin as a main component atthe above temperature, and forms a liquid-liquid two-phase system or aliquid-solid two-phase system at lower temperature. Specifically, thesolvent is selected from aliphatic hydrocarbon having 6 to 20 carbonatoms, alicyclic hydrocarbon having 6 to 20 carbon atoms, aromatichydrocarbon having 6 to 20 carbon atoms and aliphatic petroleumfraction.

Examples of the aliphatic hydrocarbon include hexane, heptane, octane,nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane,hexadecane and the like.

Examples of the alicyclic hydrocarbon include cyclohexane, cycloheptane,cyclooctane and the like.

Examples of aromatic hydrocarbon include benzene, toluene, xylene andthe like.

Examples of the aliphatic petroleum fraction include kerosene, naphthaand the like.

As the extraction solvent, these compounds may be used alone or incombination thereof. Among them, n-heptane, n-octane and naphtha areparticularly preferable.

In the present invention, the contact between the extraction solvent andreaction mixture can be performed by introducing both into the samevessel and heating to a temperature where the reaction mixture becomesthe fluid state. The contact between the extraction solvent and reactionmixture may be started by pouring, to the reaction mixture heated to thedesired temperature, the extraction solvent of the same temperature asthat of the reaction mixture, and may be started by introducing theformer into the latter.

The extraction efficiency of the unreacted substance can be improved bymixing the reaction mixture and extraction solvent with stirring at thetime of contacting the reaction mixture with the extraction solvent.Particularly, when the reaction mixture and extraction solvent form aliquid-liquid two-layer, an increase in contact area therebetween causedby stirring accelerates rapid and efficient extraction of the unreactedsubstance.

The first treatment may be performed under reflux or performed in aclosed system without reflux to prevent a reduction in amount of theextraction solvent by evaporation.

In the first treatment, the contact between the reaction mixture andextraction solvent is desirably performed at 50 to 200° C., preferably70 to 130° C., more preferably 80 to 120° C.

The amount of the extraction solvent used in the first treatment can beappropriately selected in accordance with the amount of the unreactedsubstance contained in the reaction mixture, amount of the unreactedsubstance to be removed by one purification treatment, but is desirablyin the range of 0.5 to 4 ml, preferably 1 to 2 ml, per 1 g of thereaction mixture.

In the first treatment, the contacting period is not specificallylimited, but the first treatment can be rapidly performed normally over10 to 60 minutes, particularly 20 to 30 minutes.

After the completion of the contact operation described above, thereaction mixture and extraction solvent are allowed to stand withair-cooling or cooling, thereby forming a liquid-liquid two-phase systemor a liquid-solid two-phase system. By separating the extraction solventwith decantation, the unreacted substance dissolved in this solvent canbe easily removed.

In the first treatment, a processing is carried out by performing thecontact operation and separation operation in this order, but the numberof this processing is not specifically limited. The processing may beperformed once, or may be repeated a plurality of times while replacingby a fresh extraction solvent.

According to the first treatment, since the extraction operation isperformed in the state where the reaction mixture is in a flow state,the unreacted substance can be removed in good efficiency using asmaller amount of the solvent. Since it is not necessary to maintain theliquid-solid two-phase system during the contact operation, the contacttemperature can be set, easily.

In another treatment (second treatment) which can be applied in thepurification step (i), first, the reaction mixture obtained in thepolycondensation reaction or crude highly reactive modified phenolicresin is dissolved in a reaction mixture-soluble solvent.

Examples of the soluble solvent include toluene; mixed solvent oftoluene and alcohol (e.g. ethyl alcohol, etc.); mixed solvent of tolueneand ketones (e.g. acetone, methyl ethyl ketone, methyl isobutyl ketone,etc.); and mixed solvent of toluene and ethers (e.g. tetrahydrofuran,diethyl ether, methyl tert-butyl ether, etc.).

Since a solution obtained by dissolving the crude highly reactivemodified phenolic resin in these soluble solvents has low viscosity andgood operating property, the purification processing is easilyperformed.

Then, the solution thus obtained is introduced into a solvent containingat least one compound selected from the group consisting of aliphatichydrocarbon having 10 carbon atoms or less, alicyclic hydrocarbon having10 carbon atoms or less and aliphatic petroleum fraction. As a result,the resin main component is deposited, thereby removing components whichare soluble in the solvent, that is, components remained in the state ofbeing unreacted or reacted insufficiently and the reaction solventduring the polycondensation reaction.

Examples of the hydrocarbon solvent include aliphatic or alicyclichydrocarbons such as pentane, hexane, heptane and cyclohexane; andalicyclic petroleum fraction such as naphtha. Among them, n-hexane andnaphtha are particularly preferable. The highly reactive modifiedphenolic resin obtained in the second treatment of this purificationstep (i) is in the form of powder.

In another treatment (third treatment) of the purification step (i),first, the reaction mixture or crude highly reactive modified phenolicresin obtained by the polycondensation reaction is dissolved in areaction mixture-soluble solvent.

Examples of the reaction mixture-soluble solvent include acetonitrile,methanol and dimethyl sulfoxide.

Then, the resulting solution is separated from this solution containingthe above highly reactive modified phenolic resin to form aliquid-liquid two-layer solvent system, and is brought into contact withan extraction solvent which dissolves the unreacted component to removethe component which is soluble in this extraction solvent, that is,unreacted component, component remained in the state of beinginsufficiently reacted and reaction solvent during the polycondensationreaction by extraction.

Such an extraction solvent can be appropriately selected in accordancewith the soluble solvent. For example, when using acetonitrile, methanolor dimethyl sulfoxide as the soluble solvent, a solvent containing atleast one compound selected from the group consisting of aliphatichydrocarbon having 10 carbon atoms or less, alicyclic hydrocarbon having10 carbon atoms or less and aliphatic petroleum fraction, such asn-hexane, heavy naphtha, etc. (boiling point: 80 to 150° C.) can beused.

A volume ratio (extraction solvent/solution) of the extraction solventto the crude highly reactive modified phenolic resin solution is notspecifically limited, but is normally from 10/90 to 90/10, preferablyfrom 20/80 to 80/20.

According to the third treatment, the removal efficiency of theunreacted component becomes higher and the extraction solvent can beeasily separated and removed after extraction.

In another treatment (fourth treatment) of the purification step (i),first, the reaction mixture or crude highly reactive modified phenolicresin obtained in the polycondensation reaction is allowed to stand inthe heat-molten state.

By standing the crude highly reactive modified phenolic resin in theheated state, the unreacted component, component remained in the stateof being insufficiently reacted and reaction solvent during thepolycondensation reaction are separated as a supernatant from themodified phenolic resin.

In the fourth treatment, the crude highly reactive modified phenolicresin is maintained in the heated molten state at the temperature ofnormally 70 to 200° C., preferably 80 to 180° C., more preferably 80 to150° C., and is allowed to stand for normally 15 minutes to 4 hours,preferably 20 minutes to 4 hours.

According to the fourth treatment, since the supernatant containing theunreacted component can be easily separated and removed from the highlyreactive modified phenolic resin by decantation, there is an advantagethat use of the solvent is not required in the removal of the unreactedcomponent.

In still another treatment (fifth treatment) of the purification step(i), the reaction mixture or crude highly reactive modified phenolicresin obtained by the polycondensation reaction is subjected tomolecular distillation as it is under high vacuum of 10⁻⁷ to 10⁻⁴ mmHgto remove the unreacted component, component remained in the state ofbeing insufficiently reacted and reaction solvent during thepolycondensation reaction.

In the fifth treatment, since the highly reactive modified phenolicresin containing no unreacted component in a dry state can be directlyobtained, there is an advantage that a separation process of, forexample, a solvent containing the unreacted component is not required.

In the last example (sixth treatment) which can be applied in thepurification step (i), first, the crude highly reactive modifiedphenolic resin is dissolved in a soluble solvent to prepare a reactionmixture solution.

Examples of the soluble solvent include the same organic solvents asthose exemplified in the above first treatment, and mixed solvents oftoluene and ketones, particularly a mixed solvent of toluene and methylisobutyl ketone, are suitably used.

Then, the resulting solution is mixed with water and the solution isallowed to stand to form a three-layer solvent system composed of ahighly reactive phenolic resin solution layer, a water layer and anunreacted oil layer, followed by removal of the unreacted oil layer andwater layer.

According to the sixth treatment, since the unreacted oil layer iscompletely separated from the highly reactive modified phenolic resinlayer via water, there is an advantage that the unreacted oil layer iscertainly and easily and easily removed and, furthermore, the followingpurification step (ii) is easily performed because the acid catalyst isextracted in the water layer.

In the sixth treatment, the amount of the soluble solvent is adjusted sothat a specific gravity of the highly reactive modified phenolic resinsolution layer is larger than that of water. When the amount of thesoluble solvent is too large, the specific gravity of the highlyreactive modified phenolic resin is too small (i.e. less than 1) and thewater layer unfavorably becomes a lower-most layer.

The first to sixth treatments of the purification step (i) may beperformed alone or in combination thereof.

The modified phenolic resin wherein the unreacted substance is highlyremoved has an advantage that a weight loss by heating is not recognizedand the reactivity with the epoxy resin is improved.

When the second treatment is not performed, the first treatment and thethird to sixth treatments may be used in combination with a treatment ofintroducing the crude highly reactive modified phenolic resin as it isinto a solvent containing at least one compound selected from the groupconsisting of aliphatic hydrocarbon having 10 carbon atoms or less,alicyclic hydrocarbon having 10 carbon atoms or less and aliphaticpetroleum fraction.

According to the first treatment among the first to sixth treatmentsapplied in the purification step (i), since the polycondensationreaction mixture and a specific extraction solvent are contacted eachother at the temperature where this polycondensation reaction mixture iscabable of keeping a flow state to remove the unreacted substance in theabove polycondensation reaction by extracting with an extractionsolvent, the unreacted substance extraction conditions are easily set incomparison with, for example, the second treatment of introducing thepolycondensation reaction product to deposit a solid. Furthermore, sincethe removal efficiency of the unreacted substance is high and no solventis used, simplification of the unreacted substance extraction operationand cost reduction of purification of the modified phenolic resin can beperformed.

In the above-described purification treatment (ii), the acid catalystremained in the reaction mixture is removed to obtain a highly reactivephenolic resin containing substantially no acid.

When using an organic or inorganic acid as the acid catalyst, such apurification treatment (ii) is performed by washing the reaction mixturewith water or washing with an aqueous alkali solution as it is or afterdissolving in a specific solvent to remove a catalyst residue. Accordingto washing with the aqueous alkali solution, the unreacted phenols canalso be removed, together with the acid catalyst.

The solvent in which the reaction mixture is dissolved is notspecifically limited, and examples thereof include alcohol such asmethyl alcohol and ethyl alcohol; ketones such as acetone, methyl ethylketone and methyl isobutyl ketone; ethers such as tetrahydrofuran,diethyl ether and methyl tert-butyl ether; aromatic compounds such astoluene and xylene; and a mixed solvent thereof.

Examples of the alkali used in the preparation of the aqueous alkalisolution include sodium hydroxide, potassium hydroxide, magnesiumhydroxide, calcium hydroxide, sodium hydrogencarbonate and the like.

In the purification treatment (ii), when using a solid acid as the acidcatalyst, the catalyst residue can be easily removed by filtering thereaction mixture. In this purification treatment (ii), the reactionmixture may be dissolved in the above solvent to improve the operatingproperty of processing such as filtration.

In the purification treatment (ii), when using oxalic acid as the acidcatalyst, oxalic acid can be decomposed and removed by heating thereaction mixture at the temperature of 180° C. or more.

The above-described purification treatments (i) and (ii) can beperformed in any order.

In the purification treatment (iii), the remained unreacted phenols areremoved by performing steam distillation, blowing of nitrogen or vacuumdistillation with or without removing the unreacted component, acidcatalyst, etc. by subjecting the reaction mixture to the purificationtreatment (i) and/or purification treatment (ii). The removal of theunreacted phenols may be performed by any one of these methods or byusing these methods in combination.

By removing the acid catalyst, unreacted substance and reaction solvent,which can be remained in the resin, with any of the purificationtreatments as described above, there can be obtained a highly reactivemodified phenolic resin which has no corrosiveness to the metal, becauseit substantially contains no acid, and has improved heat resistance andimproved dimensional stability because of improved reactivity with theepoxy resin. In the present specification, the term "substantiallycontaining no acid" means that any acid are not remained, or it does notshows significant corrosiveness to the metal even if a trace amount ofthe acid exists.

The modified phenolic resin molding material of the present inventioncontains the highly reactive modified phenolic resin obtained by theprocess for producing the highly reactive modified phenolic resinaccording to the present invention, and an epoxy resin. The epoxy resincauses little molding shrinkage and is excellent in heat resistance,wear resistance, chemical resistance and electrical insulatingproperties, and is optionally used in combination with a curing agentand/or a curing accelerator.

Examples of the epoxy resin include glycidyl ether type, glycidyl estertype, glycidylamine type, mixed type and alicyclic type epoxy resins.

More specifically, examples of the glycidyl ether type (phenolic) epoxyresin include bisphenol A type epoxy resin, biphenyl type epoxy resin,bisphenol F type epoxy resin, tetrabromobisphenol A type epoxy resin,tetraphenylolethane type epoxy resin, phenolic novolak type epoxy resin,o-cresylic novolak type epoxy resin, etc.;

examples of the glycidyl ether type (alocoholic) epoxy resin includepolypropylene glycol type epoxy resin, hydrogenated bisphenol A typeepoxy resin, etc.;

examples of the glycidyl ester type include hexahydrophthalic anhydridetype epoxy resin, dimer acid type epoxy resin, etc.;

examples of the glycidylamine type epoxy resin includediaminodiphenylmethane type epoxy resin, isocyanuric acid type epoxyresin, hydantoic acid type epoxy resin, etc.; and

examples of the mixed type epoxy resin include p-aminophenol type epoxyresin, p-oxybenzoic acid type epoxy resin, etc. Among the above epoxyresins, bisphenol A type epoxy resin, biphenyl type epoxy resin,glycidylamine type epoxy resin and phenolic novolak type epoxy resin arepreferable: Those prepared by using two or more epoxy resins incombination can also be used.

In the present invention, a mixing ratio of the highly reactive modifiedphenolic resin to the epoxy resin is not specifically limited, but ispreferably from 10/90 to 90/10 (parts by weight), more preferably from20/80 to 80/20 (parts by weight), based on the total of 100 parts byweight of the highly reactive modified phenolic resin and epoxy resin.

When the mixing ratio of the modified phenolic resin is less than 10parts by weight, the heat resistance and moisture resistance of theresulting molded article are not sufficient. On the other hand, when itexceeds 90 parts by weight, the molding temperature is liable to becometoo high.

As the curing agent and/or curing accelerator used in the modifiedphenolic resin molding material of the present invention, there can beused various curing agents and curing accelerators used in curing of theepoxy resin. Examples of the curing agent include cyclic amines,aliphatic amines, polyamides, aromatic polyamines and acid anhydrides.

Specifically, examples of the cyclic amines includehexamethylenetetramine, etc.; and examples of the aliphatic aminesinclude diethylenetriamine, triethylenetetramine,tetraethylenepentamine, diethylaminopropylamine, N-aminoethylpiperamine,isophoronediamine, bis(4-amino-3-methylcyclohexyl)methane,menthanediamine, etc.

Examples of the polyamides include vegetable oil fatty acid (dimer ortrimer acid), aliphatic polyamine condensate, etc.; and

examples of the aromatic polyamines include m-phenylenediamine,4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone,m-xylenediamine, etc.

Examples of the acid anhydrides include phthalic anhydride,tetrahydrophthalic anhydride, hexahydrophthalic anhydride, trimelliticanhydride, pyromellitic anhydride, benzophenonetetracarboxylicanhydride, chlorendic anhydride, dodecynylsuccinic anhydride,methyltetrahydrophthalic anhydride,methylendomethylenetetrahydrophthalic anhydride, etc.

Examples of the curing accelerator include diazabicycloalkenes andderivatives thereof, such as 1,8-diazabicyclo(5,4,0)undecene-7, etc.;tertiary amines such as triethylenediamine, benzyldimethylamine,triethanolamine, dimethylaminoethanol, tris(dimethylaminomethyl)phenol,etc.; imidazoles such as 2-methylimidazole, 2-ethyl-4-methylimidazole,2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-heptadecylimidazole,etc.; organic phosphines such as tributylphosphine,methyldiphenylphosphine, triphenylphosphine, etc.; tetra-substitutedphosphonium-tetra-substituted borates such as tetraphenylphosphoniumtetraphenylborate, etc.; tetraphenylboron salts such as2-ethyl-4-methylimidazole tetraphenylborate, N-methylmorpholinetetraphenolborate, etc.; Lewis acids such as boron trifluoride-aminecomplex, etc.; Lewis bases such as dicyanediamide, dihydrazide adipate,etc.; and polymercaptane, polysulfide, etc. These curing agents andcuring accelerators may be used alone or in combination thereof.

The above modified phenolic resin molding material may further containan inorganic filler, in addition to the above highly reactive modifiedphenolic resin and epoxy resin and, if necessary, curing and/or curingaccelerator.

The strength and dimensional stability of the resulting molded articlecan be further improved by adding the inorganic filler to the resinmolding material.

As the inorganic filler, there can be used various inorganic fillerswhich can be used as the inorganic filler or reinforcement in theplastic material, and examples thereof include fiber reinforcements suchas glass fiber, carbon fiber, phosphor fiber and boron fiber; hydratedmetal oxides such as aluminum hydroxide and magnesium hydroxide; metalcarbonates such as magnesium carbonate and calcium carbonate; metalborates such as magnesium borate; and inorganic fillers such as silica,mica and fused silica.

The amount of the inorganic filler blended is not specifically limited,but is normally from 20 to 2000 parts by weight, preferably from 20 to800 parts by weight, more preferably from 50 to 600 parts by weight,based on 100 parts by weight of the resin component prepared by addingthe epoxy resin to the highly reactive modified phenolic resin.

The above modified phenolic resin molding material may further containadditives, if necessary. Examples of the additives include inner releaseagents such as silicone, wax; coupling agents; flame retardants;photostabilizers; antioxidants; pigments; and bulking agents.

The above-described modified phenolic resin molding material of thepresent invention is prepared by mixing the highly reactive modifiedphenolic resin and epoxy resin and, if necessary, curing agent and/orcuring accelerator, inorganic filler and various additives, and isapplied in the production of the molded article.

In the present invention, the mixing order of the highly reactivemodified phenolic resin and epoxy resin, and optional components such ascuring agent is not specifically limited. For example, a fine powderedmolding powder (compound) can be prepared by kneading the highlyreactive modified phenolic resin and epoxy resin, adding the curingagent (curing accelerator), sufficiently mixing them and optionallyadding the inorganic filler and other additives, followed by mixing.

Specifically, such a compound can be prepared by the followingprocedures.

1) The highly reactive modified phenolic resin and epoxy resin are mixedwith stirring at room temperature using an automatic mortar.

2) To the stirred mixture, other additives such as curing agent and/orcuring accelerator, wax, etc. are added, followed by mixing.

3) The inorganic filler is added, followed by mixing.

4) After futher mixing for 3 to 10 minutes using rolls adjusted to 80 to90° C. and returning to room temperature, followed by grinding theresultant mixture to form a compound.

In this case, the addition of the inorganic filler and other additivesis performed separately after mixing the highly reactive modifiedphenolic resin and epoxy resin, but can also be performed at any time.

The modified phenolic resin molding material of the present inventioncan be formed into a molding material by various resin molding meanswhich have hitherto been known. Examples of the molding means includecompression molding, injection molding, extrusion molding, transfermolding and casting molding.

More specifically, when the molding article is produced by transfermolding using the modified phenolic resin molding material of thepresent invention, the molding conditions of a molding temperature of120 to 200° C., an ejection pressure of 5 to 300 Kgf/cm², preferably 20to 300 Kgf/cm², a clamping pressure of 50 to 250 Kgf/cm² and a moldingtime of 1 to 10 minutes are preferable.

The molded article thus molded is desirably post-cured by heating at thetemperature of 150 to 300° C. for 0.5 to 24 hours.

The heat resistance of the molded article can be further improved bysubjecting the molded article to post-curing.

In the modified phenolic resin molding material according to the presentinvention, since a highly reactive modified phenolic resin having lowmelt viscosity and high reactivity with the epoxy resin, and beingimproved in heat resistance, adhesion and low moisture absorptionproperty is used, the moldability is good and the mechanicalcharacteristics (e.g. dimensional stability, etc.), moisture resistance,heat resistance, adhesion and moisture absorption property of theresulting molded article are improved. In the modified phenolic resinmolding material according to the present invention, when using amodified phenolic resin containing substantially no acid, thecorrosiveness to the metal member can be lowered. In addition, themechanical strength and electrical insulating properties of the moldedarticle can also be improved by adding inorganic fillers.

Accordingly, this modified phenolic resin molded article is useful aselectrical/electronic parts, such as printed board, insulating material,sealing material, etc., and is also useful as semiconductor sealingmaterials on which improvements of thermal resistance, dimensionalstability as a measure for stress damage caused by high integration, andmoisture absorption property are demanded.

EFFECT OF THE INVENTION

According to the first to sixth processes of producing the highlyreactive modified phenolic resin of the present invention, the molecularweight lowerly step, which was essential in a conventional method, canbe eliminated and it is possible to produce in one step a highlyreactive modified phenolic resin having a low resin melt viscosity andhigh reactivity with the epoxy resin, and exhibiting particularlyexcellent adhesion and low moisture absorption property, when thearomatic hydrocarbon compound is added to the raw materials.

According to the first to sixth processes of producing the highlyreactive modified phenolic resin of the present invention, a highlyreactive modified phenolic resin having above-described excellentcharacteristics can be stably and economically supplied by using apolycondensation raw oil capable of being stably and efficientlysupplied and advantageous in view of the cost, that is, a distilled oilhaving the specific physical properties and being obtained by thecatalytic cracking step or thermal cracking step in the petroleumrefining process, without subjecting to a treatment such as vacuumdistillation, etc.

According to the processes of producing the highly reactive modifiedphenolic resin of the present invention, it is possible to produce ahighly reactive modified phenolic resin which has low resin meltviscosity and high reactivity with the epoxy resin and shows excellentheat resistance, adhesion and low moisture absorption property, andwhich has no corrosiveness because it substantially contains no acid, bysubjecting the highly reactive modified phenolic resin obtained by thepolycondensation reaction to a purification treatment to remove theunreacted component, acid catalyst, etc.

The modified phenolic resin molding material of the present inventioncontains the highly reactive modified phenolic resin obtained by theprocess of the present invention and epoxy resin, and can provide amolding material capable of producing a molded article having goodmoldability, excellent mechanical characteristics (e.g. dimensionalstability, etc.), excellent moisture resistance and heat resistance,particularly electrical/electronic parts and semiconductor sealingmaterials.

EXAMPLES

The following Examples further illustrate the present invention indetail but are not to be construed to limit the scope thereof.

In the following Examples, "parts" are by weight unless otherwisestated. The properties of the raw oil used as the reaction raw materialare shown in the following Table 1 to Table 3.

                  TABLE 1                                                         ______________________________________                                                       Raw oil X                                                      ______________________________________                                        Kind of raw oil  Fluid catalytic cracking                                        bottom distillate                                                            Average molecular weight 251                                                  Boiling point (° C.) 254 to 468                                        Fraction of aromatic 0.70                                                     hydrocarbon (fa)                                                              Hydrogen content of aromatic  33                                              ring (Ha) (%)                                                               ______________________________________                                         Note:                                                                         Average molecular weight: value measured according to vapor pressure          osmometory                                                                    Boiling point: value of ° C. in terms of the atmospheric pressure,     measured according to ASTM D1160                                              Raw oil X: obtained by distilling column bottom oil prepared by fluid         catalytic cracking (FCC) of vacuum gas oil                               

                                      TABLE 2                                     __________________________________________________________________________            Raw oil A                                                                            Raw oil B                                                                            Raw oil C                                                                            Raw oil D                                                                            Raw oil E                                 __________________________________________________________________________    Process FCC    FCC    FCC    Delayed                                                                              Flexicoa                                        coaker ker                                                                Raw oil Desulfurized Desulfurized Desulfurized Topped crude Topped                                              crude                                       for the vacuum heavy vacuum heavy vacuum heavy oil oiol                       process gas oil gas oil gas oil                                                Desulfurized Desulfurized Desulfurized Vacuum Vacuum                          heavy oil heavy oil heavy oil bottom oil bottom oil                             Topped crude  Tar sand                                                        oil                                                                        Average 250 235 224 226 248                                                   molecular                                                                     weight                                                                        Boiling 196 to 455 206 to 470 222 to 437 193 to 483 264 to 463                point (° C.)                                                           Fraction of 0.48 0.51 0.61 0.62 0.67                                          aromatic                                                                      hydrocarbon (fa)                                                              Hydrogen 51 47 29 32 27                                                       content of                                                                    aromatic                                                                      ring (Ha) (%)                                                               __________________________________________________________________________     Note:                                                                         Average molecular weight: value measured according to vapor pressure          osmometory                                                                    Boiling point: value of ° C. in terms of the atmospheric pressure,     measured according to ASTM D1160                                         

                  TABLE 3                                                         ______________________________________                                                 Raw oil Raw oil  Raw oil   Raw oil                                     P Q R S                                                                     ______________________________________                                        Average molecular                                                                        138       148      165     213                                       weight (VPO)                                                                  Boiling Point (° C.) 200 to 300 200 to 360 200 to 420 210 to         ______________________________________                                                                              355                                      Note:                                                                         Average molecular weight: value measured according to vapor pressure          osmometory                                                                    Boiling point: value of ° C. in terms of the atmospheric pressure,     measured according to ASTM D1160                                              Raw oil PS: obtained by refining hightemperature tar obtained from coke       oven tar to prepare each boiling point fraction                          

The number-average molecular weight, reactivity with the epoxy resin(judged by the gelation time: the shorter, the higher the reactivity),resin melt viscosity and hydroxyl group equivalent measured in thefollowing Examples were measured by the following devices or measuringmethods.

<Number-average Molecular Weight>

Measuring device: GPC device HLC-8020 (column: TSK gel 3000HXL+TSK gel2500HXL X 3, standard substance: polystyrene) manufactured by TosoCorporation

The molecular weight was calculated from the resulting data, usingpolystyrene as the standard substance.

<Glass Transition Temperature>

Measuring system: dynamic viscoelasticity method

Measuring device: DVE RHEOSPECTOLER DVE-4V type, manufactured byRheology Co., Ltd.

Loading system: tensile loading

Measuring frequency: 10 Hz

Heating rate: 5° C./min.

Dynamic measuring displacement: ±5×10⁻⁴ cm

Test piece: 4 mm in width×1 mm in thickness×30 mm in span

<Hydroxyl Group Equivalent>

Measured according to an acetylation chloride method.

<ICI Viscosity>

Measured by using an ICI corn plate viscometer manufactured by ICI Co.

<Gelation Time>

Measured at 170° C. according to JIS K 6910.

<Heating Weight Loss>

A weighed sample (10 g) was put in a constant temperature bath kept at apredetermined temperature and maintained for 2 hours, and then a weightratio of the sample before and after subjecting to a high-temperaturetreatment was determined and was taken as a heating weight loss.

<Shore Hardness Immediately After Molding>

Measured by using a Shore hardness tester.

<Flexural Strength and Modulus>

Measured according to JIS K 6911.

<Peal Strength>

Measured according to JIS K 6481.

<Moisture Absorption Rate>

A molded article was made according to JIS K 7209 and a difference inweight of the molded article before and after treating underpredetermined conditions was determined.

Example 1

100 g of a raw oil X and 150 g of phenol were charged in a 1 liter glassreaction vessel, and the mixture was maintained at 40° C. while stirringat a rate of 250 to 350 rpm. After the temperature of the mixture duringstirring became stable, a mixture of formalin (aqueous 37 wt % solution)(116.2 g) and sulfuric acid (97wt %, 53.1 g) was added dropwise over 20minutes with paying attention to an increase in temperature. After thecompletion of the dropwise addition, the reaction was continued withmaintaining the temperature at 95° C. for 100 minutes to obtain areaction product.

The above reaction product was dissolved by introducing into 450 ml of atoluene/methyl isobutyl ketone (mixing ratio: 2/1) mixed solvent and theresulting resin mixed solution was washed with distilled water to removean acid, and then the mixed solvent was removed by using an evaporator.Thereafter, the unreacted phenol was removed by steam distillation andwater was then removed by blowing nitrogen to obtain 242 g of a crudehighly reactive modified phenolic resin.

Then, the crude highly reactive modified phenolic resin in the heatedmolten state was poured into 4800 ml of n-hexane to remove the unreactedraw oil and to deposit a resin, which was filtered and dried to obtain203 g of a highly reactive modified phenolic resin.

The number-average molecular weight, melt viscosity at 150° C. andhydroxyl group equivalent of the resulting highly reactive modifiedphenolic resin were measured. The results are shown in Table 4, togetherwith the reaction conditions.

Examples 2 to 5

The highly reactive modified phenolic resin in the yield shown in Table4 were obtained in the same manner as in Example 1, except that thereaction conditions were changed as shown in Table 4.

The number-average molecular weight, melt viscosity at 150° C. andhydroxyl group equivalent of the resulting highly reactive modifiedphenolic resins were measured. The results are shown in Table 4,together with the reaction conditions.

Example 6

100 g of a raw oil X, 150 g of phenol and 80 g of formalin (aqueous 37wt % solution) were charged in a 1 liter glass reaction vessel, and themixture was maintained at 40° C. while stirring at a rate of 250 to 350rpm. After the temperature of the mixture became stable, sulfuric acid(97 wt %, 37 g) was added dropwise over 14 minutes with paying attentionto an increase in temperature. After the completion of the dropwiseaddition, the reaction was continued with maintaining the temperature at95° C. for 106 minutes to obtain a reaction product.

The above reaction product was dissolved by introducing into 450 ml of atoluene/methyl isobutyl ketone (mixing ratio: 2/1) mixed solvent and theresulting resin mixed solution was washed with distilled water to removean acid, and then the mixed solvent and unreacted phenols were removedby using an evaporator to obtain 197 g of a crude highly reactivemodified phenolic resin.

Then, the crude highly reactive modified phenolic resin in theheat-molten state was poured into 5200 ml of n-hexane to remove theunreacted raw oil and to deposit a resin, which was filtered and driedto obtain 173 g of a highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 4, together with the reaction conditions.

Example 7

The highly reactive modified phenolic resin in the yield shown in Table4 was obtained in the same manner as in Example 1, except that thereaction conditions were changed as shown in Table 4.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 4, together with the reaction conditions.

Example 8

9.58 parts by weight of the highly reactive modified phenolic resinobtained in Example 1 and 14.48 parts by weight of a biphenyl type epoxyresin (trade name YX-4000H, manufactured by Yuka Shell Epoxy Co., Ltd.)were mixed with stirring at room temperature using an automatic mortar,and 0.49 parts by weight of triphenylphosphine (TPP) as a curingcatalyst was then added to obtain a curing accelerator-containing resinmixture.

The gelation time of this curing accelerator-containing resin mixturewas measured. The resulting gelation time is shown in Table 5.

0.25 parts by weight of carnauba wax was further added to the resultingcompound, and 0.20 parts by weight of carbon black and 75 parts byweight of a fused silica (CRS1102-GT200T, manufactured by Tatsumori Co.,Ltd.) as an inorganic filler were then added, followed by mixing. Theresulting mixture was further mixed by using rolls adjusted to 80 to 90°C. for 3 to 10 minutes, cooled to room temperature and then ground toobtain a compound (molding material). The formulation composition ofthis compound is shown in Table 5.

The resulting compound was subjected to transfer molding under theconditions of 175° C. for 90 seconds and further post-cured at 175° C.for 6 hours to obtain a molded article.

The Shore hardness immediately after molding, glass transitiontemperature, flexural characteristics and moisture absorption rate ofthe resulting compound were measured. The results are shown in Table 5.

Examples 9 to 14

The curing accelerator-containing resin mixtures, the compounds and themolded articles were produced in the same manner as in Example 8, exceptthat the highly reactive modified phenolic resins obtained in Examples 2to 7 were used in place of the highly reactive modified phenolic resinobtained in Example 1, respectively and that the formulation ratios ofthe highly reactive modified phenolic resins to the epoxy resin werechanged to the values shown in Table 5.

The gelation time of each resulting curing accelerator-containing resinmixtures and physical properties of the molded articles are shown inTable 5.

                                      TABLE 4                                     __________________________________________________________________________                Example                                                                            Example                                                                            Example                                                                            Example                                                                            Example                                                                            Example                                                                            Example                               1 2 3 4 5 6 7                                                               __________________________________________________________________________    Raw oil (g) 100  200  100  100  100  100  100                                   Phenol (g) 150 150 206 263 263 150 151                                        Formalin (g) 116 80 136 181 165 80 80                                         (37 wt %)                                                                     Acid catalyst (g) 53 37 62 85 74 37 14                                        Kind of acid -- sulfuric sulfuric sulfuric sulfuric sulfuric sulfuric                                                 Sulfuric                              catalyst  acid acid acid acid acid acid acid                                  Reaction (° C.) 95 95 95 95 95 95 95                                   temperature                                                                   Reaction time (min.) 120 120 120 120 120 360 120                              Dropping mode -- sulfuric sulfuric sulfuric sulfuric sulfuric sulfuric                                                sulfuric                                acid/ acid/ acid/ acid/ acid/ acid acid                                       formalin formalin formalin formalin formalin                                Yield (wt %) 203 198 250 338 331 173 166                                      (based on raw oil)                                                            Viscosity (p) 5.2 0.3 1.4 1.3 1.0 0.6 0.4                                     at 150° C.                                                             (ICI viscometer)                                                              Number-average -- 580 244 420 481 392 284 320                                 molecular                                                                     weight (GPC)                                                                  Hydroxyl group (g/eq) 129 147 126 119 121 137 137                             equivalent                                                                  __________________________________________________________________________

                                      TABLE 5                                     __________________________________________________________________________                             Ex. 8                                                                             Ex. 9                                                                             Ex. 10                                                                            Ex. 11                                                                            Ex. 12                                                                            Ex. 13                                                                            Ex. 14                       __________________________________________________________________________    Modified phenolic                                                                         Example 1                                                                           pbw    9.58                                                   resin Example 2 pbw  10.35                                                     Example 3 pbw   9.46                                                          Example 4 pbw    9.12                                                         Example 5 pbw     9.21                                                        Example 6 pbw      9.94                                                       Example 7 pbw       9.94                                                     Epoxy resin YX-4000H pbw 14.48 13.71 14.60 14.94 14.85 14.12 14.12                                                            Curing TPP pbw 0.49                                                          0.49 0.49 0.49 0.49 0.49                                                      0.49                           accelerator                                                                   Fused silica CRS1102- pbw 75 75 75 75 75 75 75                                 GT200T                                                                       Carnauba wax  pbw 0.25 0.25 0.25 0.25 0.25 0.25 0.25                          Carbon black  pbw 0.20 0.20 0.20 0.20 0.20 0.20 0.20                          Gelation time  (170° C./SEC) 41 43 37 35 34 41 41                      Shore hardness immediately  -- 72 70 72 76 75 73 73                           after molding                                                                 Glass transition temperature  (° C.) 129 126 128 139 140 127 128       (Tg)                                                                          Flexural strength Room (kgf/mm.sup.2) 14.2 13.3 14.5 16.1 15.7 14.0                                                          14.0                            temperature                                                                  Flexural modulus Room (kgf/mm.sup.2) 1690 1630 1700 1750 1730 1710 1720        temperature                                                                  Moisture 85° C./ (wt %) 0.24 0.22 0.24 0.26 0.26 0.21 0.21                                                             absorption rate 85%-72                                                       hr                              85° C./ (wt %) 0.33 0.31 0.34 0.35 0.35 0.32 0.31                      85%-168 hr                                                                 __________________________________________________________________________     *pbw: parts by weight                                                    

Example 15

100 g of a raw oil X, 263 g of phenol, 164 g of formalin (aqueous 37 wt% solution) and 11 g of sulfuric acid (97 wt %) were charged in a 1liter glass reaction vessel, and the mixture was heated to 95° C. over20 minutes while stirring at a rate of 250 to 350 rpm and reacted withmaintaining at 95° C. for 100 minutes to obtain a reaction product.

The above reaction product was purified in the same manner as in Example1, except that the unreacted phenol was removed by nitrogen blowing at160° C. to obtain 290 g of a crude phenolic resin, and the crudephenolic resin in the heat-molten state was poured into 6000 ml ofn-hexane.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 6, together with the reaction conditions.

Example 16

100 g of a raw oil X, 206 g of phenol, 136 g of formalin (aqueous 37 wt% solution) and 70 g of Daiya-ion SK1B (manufactured by MitsubishiChemical Co., Ltd.) as an acidic ion exchange resin were charged in a 1liter glass reaction vessel, and the mixture was heated to 120° C. over20 minutes while stirring at a rate of 250 to 350 rpm and reacted withmaintaining at 120° C. for 280 minutes to obtain a reaction product.

The above reaction product was filtered by using a metal mesh of 60 meshto remove Daiya-ion SK1B. The resulting resin was subjected to steamdistillation at 160° C., to remove the unreacted phenol and water wasthen removed by blowing nitrogen to obtain 234 g of a crude highlyreactive modified phenolic resin.

Then, the crude highly reactive modified phenolic resin in theheat-molten state was poured into 4800 ml of n-hexane to remove theunreacted raw oil and to deposit a resin, which was filtered and driedto obtain 215 g of a highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 6, together with the reaction conditions.

Example 17

A paraffin component and a component having low reactivity in 120 g of araw oil X shown in Table 1 were removed according to ASTM-D-2549. Activealumina gel (manufactured by Wako Pure Pharmaceutical Industries Co.,Ltd.) and silica gel (manufactured by Fuji Dewinson Co., Ltd.) were usedfor a column, and n-pentane, diethyl ether, chloroform and ethyl alcoholwere used as a developer.

100 g of the raw oil obtained above, 263 g of phenol, 181 g of formalin(aqueous 37 wt % solution) and 11 g of sulfuric acid (97 wt % by weight)were charged in a 1 liter glass reaction vessel, and the mixture washeated to 95° C. over 20 minutes while stirring at a rate of 250 to 350rpm and reacted with maintaining at 95° C. for 100 minutes to obtain areaction product.

The above reaction product was dissolved by introducing in 450 ml of atoluene/methyl isobutyl ketone (mixing ratio: 2/1) mixed solvent and theresulting resin mixed solution was washed with distilled water to removean acid, and then the mixed solvent was removed by using an evaporator.Furthermore, the unreacted phenol was removed by blowing nitrogen at160° C. to obtain 267 g of a crude highly reactive modified phenolicresin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 6, together with the reaction conditions.

Examples 18 to 20

Curing accelerator-containing resin mixtures, the compounds and moldedarticles were obtained in the same manner as in Example 8, except thatthe highly reactive modified phenolic resin obtained in Examples 15 to17 were used.

The composition, properties, etc. are shown in Table 7.

                  TABLE 6                                                         ______________________________________                                                     Example Example   Example                                          15 16 17                                                                    ______________________________________                                        Raw oil    (g)     100       100     100                                        Phenol (g) 263 206 263                                                        Formalin (37 (g) 164 136 181                                                  wt %)                                                                         Acid catalyst (g)  11  70  11                                                 Kind of acid -- sulfuric Daiya-ion sulfuric                                   catalyst  acid SK1B acid                                                      Reaction (° C.)  95 120  95                                            temperature                                                                   Reaction time (min.) 120 300 120                                              Yield  (wt %) 264 215 267                                                     (based on                                                                     raw oil)                                                                      Viscosity (p) 2.2 2.1 1.9                                                     at 150° C. (ICI                                                        viscometer)                                                                   Number-average -- 473 461 487                                                 molecular                                                                     weight (GPC)                                                                  Hydroxyl group (g/eq) 118 123 119                                             equivalent                                                                  ______________________________________                                    

                  TABLE 7                                                         ______________________________________                                                           Ex. 18                                                                              Ex. 19  Ex. 20                                       ______________________________________                                        Modified  Example 15                                                                              pbw      9.07                                               phenolic  Example 16 pbw  9.31                                                resin Example 17 pbw   9.12                                                   Epoxy resin YX-4000H pbw 14.99  14.75  14.94                                  Curing TPP pbw 0.49 0.49 0.49                                                 accelerator                                                                   Fused silica CRS1102- pbw 75 75 75                                             GT200T                                                                     Carnauba wax    pbw      0.25    0.25  0.25                                     Carbon black  pbw 0.20 0.20 0.20                                              Gelation time  (170° C./ 35 36 35                                       SEC)                                                                         Shore hardness immediately -- 75 73 75                                        after molding                                                                 Glass transition temperature (° C.) 136  134  136                      (Tg)                                                                        Flexural strength                                                                       Room      (kgf/    15.9  15.5  16.1                                    temperature mm.sup.2)                                                        Flexural modulus Room (kgf/ 1750 1700 1730                                     temperature mm.sup.2)                                                        Moisture 85° C./ (wt %) 0.24 0.24 0.24                                 absorption rate 85%-72 hr                                                      85° C./ (wt %) 0.34 0.33 0.34                                          85%-168 hr                                                                 ______________________________________                                         *pbw: parts by weight                                                    

EXAMPLE 21

100 g of a raw oil X, 263 g of phenol and 100 g of m-xylene were chargedinto a 1 liter glass reaction vessel, and the mixture was maintained at40° C. while stirring at a rate of 250 to 350 rpm. After the temperaturebecame stable, a mixture of formalin (aqueous 37 wt % solution) (164 g)and sulfuric acid (97 wt %, 74 g) was added dropwise over 20 minutes,with paying attention to an increase in temperature. After thecompletion of the dropwise addition, the reaction was performed withmaintaining the temperature at 95° C. for 100 minutes to obtain areaction product.

The above reaction product was purified in the same manner as in Example15, except that, after the nitrogen blowing, 342 g of a crude phenolicresin was obtained and the crude phenolic resin was poured into 7000 mlof n-hexane.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 8, together with the reaction conditions.

EXAMPLE 22

100 g of a raw oil X, 206 g of phenol, 100 g of m-xylene and 70 g ofDaiya-ion SK1B (manufactured by Mitsubishi Chemical Co., Ltd.,) werecharged into a 1 liter glass reaction vessel, and the mixture wasmaintained at 40° C. while stirring at a rate of 250 to 350 rpm. Afterthe temperature became stable, 136 g of formalin (aqueous 37 wt %solution) was added dropwise over 20 minutes, with paying attention toan increase in temperature. After the completion of the dropwiseaddition, the reaction was performed with maintaining the temperature at120° C. for 280 minutes to obtain a reaction product.

The above reaction product was filtered by using a metal mesh of 60 meshto remove Daiya-ion SK1B. The unreacted phenol was removed by blowingnitrogen into the resulting resin at 160° C. to obtain 282 g of a crudehighly reactive modified phenolic resin.

Then, the crude highly reactive modified phenolic resin in theheat-molten state was poured into 7000 ml of n-hexane to remove theunreacted oil and to deposit a resin, which was filtered and dried toobtain 256 g of a highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 8, together with the reaction conditions.

EXAMPLE 23

100 g of the raw oil X wherein the paraffin component and componenthaving low reactivity were removed in the same manner as in Example 17,263 g of phenol and 100 g of m-xylene were charged into a 1 liter glassreaction vessel, and the mixture was maintained at 40° C. while stirringat a rate of 250 to 350 rpm. After the temperature became stable, amixture of formalin (aqueous 37 wt % solution) (181 g) and sulfuric acid(97 wt %, 85 g) was added dropwise over 20 minutes, with payingattention to an increase in temperature. After the completion of thedropwise addition, the reaction was performed with maintaining thetemperature at 95° C. for 100 minutes to obtain a reaction product.

The above reaction product was purified in the same manner as in Example17 to obtain 314 g of a highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 8, together with the reaction conditions.

EXAMPLE 24 TO 26

Curing accelerator-containing resin mixtures, the compounds and moldedarticles were obtained in the same manner as in Example 8, except thatthe highly reactive modified phenolic resins obtained in Examples 21 to23 were used.

The compositions, properties, etc. are shown in Table 9.

                  TABLE 8                                                         ______________________________________                                                     Example Example   Example                                          21 22 23                                                                    ______________________________________                                        Raw oil    (g)     100       100     100                                        Phenol (g) 263 206 263                                                        Formalin (g) 164 136 181                                                      m-xylene (g) 100 100 100                                                      Acid catalyst (g)  74  70  85                                                 Kind of acid -- sulfuric Daiya-ion sulfuric                                   catalyst  acid SI1B acid                                                      Reaction (° C.)  95 120  95                                            temperature                                                                   Reaction time (min.) 120 300 120                                              Yield  (wt %) 311 256 314                                                     (based on                                                                     raw oil)                                                                      Viscosity (p) 1.0 1.3 1.2                                                     at 150° C. (ICI                                                        viscometer)                                                                   Number-average -- 402 424 466                                                 molecular                                                                     weight (GPC)                                                                  Hydroxyl group (g/eq) 123 130 125                                             equivalent                                                                  ______________________________________                                    

                  TABLE 9                                                         ______________________________________                                                           Ex. 24                                                                              Ex. 25  Ex. 26                                       ______________________________________                                        Modified  Example 21                                                                              pbw      9.31                                               phenolic  Example 22 pbw  9.62                                                resin Example 23 pbw   9.40                                                   Epoxy resin YX-4000H pbw 14.75  14.44  14.66                                  Curing TPP pbw 0.49 0.49 0.49                                                 accelerator                                                                   Fused silica CRS1102- pbw 75 75 75                                             GT200T                                                                     Carnauba wax    pbw      0.25    0.25  0.25                                     Carbon black  pbw 0.20 0.20 0.20                                              Gelation time  (170° C./ 35 38 43                                       SEC)                                                                         Shore hardness immediately -- 75 73 72                                        after molding                                                                 Glass transition temperature (° C.) 136  135  129                      (Tg)                                                                          Peel strength (kgf/ 2.3  2.3  2.2                                              cm)                                                                        Flexural strength                                                                       Room      (kgf/    15.8  15.7  14.2                                    temperature mm.sup.2)                                                        Flexural modulus Room (kgf/ 1710 1720 1700                                     temperature mm.sup.2)                                                        Moisture 85° C./ (wt %) 0.25 0.24 0.25                                 absorption rate 85%-72 hr                                                      85° C./ (wt %) 0.34 0.33 0.34                                          85%-168 hr                                                                 ______________________________________                                         *pbw: parts by weight                                                    

EXAMPLE 27

100 g of a raw oil X and 206 g of phenol were charged into a 1 literglass reaction vessel, and the mixture was maintained at 40° C. whilestirring at a rate of 250 to 350 rpm. After the temperature becamestable, a mixture of formalin (aqueous 37 wt % by weight solution)(136.4 g) and sulfuric acid (97 wt % by weight, 62.3 g) was addeddropwise over 20 minutes, with paying attention to an increase intemperature. After the completion of the dropwise addition, the reactionwas performed with maintaining at 95° C. for 100 minutes to obtain areaction product.

The above reaction product was dissolved in 450 ml of a toluene/methylisobutyl ketone (mixing ratio: 2/1) mixed solvent and the resultingresin mixed solution was washed with distilled water to remove an acidand then concentrated by using an evaporator until the solventconcentration became 10% by weight, thereby to obtain a resin varnish.

Then, the resin varnish was poured into 5800 ml of n-hexane to removethe unreacted raw oil and to deposit a resin, which was filtered toobtain 273 g of a crude highly reactive modified phenolic resin.

Furthermore, the resulting crude highly reactive modified phenolic resinwas subjected to steam distillation at 160° C. to remove the unreactedphenol, and water was removed by blowing nitrogen to obtain 236 g of ahighly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 10, together with the reaction conditions.

EXAMPLE 28

100 g of a raw oil X, 263 g of phenol and 73 g of an acidic ion exchangeresin Dia-ion SK1B (manufactured by Mitsubishi Chemical Co., Ltd.,) werecharged into a 1 liter glass reaction vessel, and the mixture wasmaintained at 40° C. while stirring at a rate of 250 to 350 rpm.

After the temperature became stable, 164.8 g of formalin (aqueous 37 wt% by weight solution) was added dropwise over 20 minutes, with payingattention to an increase in temperature. After the completion of thedropwise addition, the reaction was performed with maintaining at 120°C. for 280 minutes to obtain a reaction product.

The above reaction product was dissolved by introducing into 450 ml ofdimethyl sulfoxide, and the resin mixed solution was filtered by using ametal mesh of 60 mesh to remove the used ion exchange resin.

The resin mixed solution was subjected to liquid-liquid extraction using350 ml of heavy naphtha having a boiling point of 80 to 150° C. in aseparating funnel to remove the unreacted raw oil, thereby obtaining acrude highly reactive modified phenolic resin.

Furthermore, the resulting crude highly reactive modified phenolic resinwas subjected to steam distillation at 160° C. to remove dimethylsulfoxide and the unreacted phenol, and water was removed by blowingnitrogen to obtain 203 g of a highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 10, together with the reaction conditions.

EXAMPLE 29

A crude highly reactive modified phenolic resin obtained in the samemanner as in Example 6 was subjected to steam distillation at 160° C. toremove the unreacted phenol, and then water was removed by blowingnitrogen at the same temperature to obtain 197 g of a crude highlyreactive modified phenolic resin.

Then, the crude highly reactive modified phenolic resin in theheat-molten state was cooled to 120° C. and then allowed to stand at thesame temperature to remove the unreacted raw oil separated in the upperlayer, thereby obtaining 178 g of a highly reactive modified phenolicresin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 10, together with the reaction conditions.

EXAMPLE 30

100 g of the raw oil X obtained in the same manner as in Example 17,wherein a paraffin component and a component having low reactivity wereremoved, and 263 g of phenol were charged into a 1 liter glass reactionvessel, and the mixture was maintained at 40° C. while stirring at arate of 250 to 350 rpm. After the temperature became stable, a mixtureof formalin (aqueous 37 wt % solution) (165 g) and sulfuric acid (97 wt%, 73.7 g) was added dropwise over 20 minutes, with paying attention toan increase in temperature. After the completion of the dropwiseaddition, the reaction was performed with maintaining at 95° C. for 100minutes to obtain a reaction product.

The above reaction product was dissolved by introducing into 450 ml of atoluene/methyl isobutyl ketone (mixing ratio: 2/1) mixed solvent and theresulting resin mixed solution was washed with distilled water to removean acid, and then the mixed solvent and unreacted phenol were removed byusing an evaporator to obtain 242 g of a crude highly reactive modifiedphenolic resin.

Then, the resulting crude highly reactive modified phenolic resin wassubjected to molecular distillation to obtain 212 g of a highly reactivemodified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 10, together with the reaction conditions.

EXAMPLE 31

100 g of a raw oil X and 263 g of phenol were charged into a 1 literglass reaction vessel, and the mixture was maintained at 40° C. whilestirring at a rate of 250 to 350 rpm. After the temperature becamestable, a mixture of formalin (aqueous 37 wt % solution) (164.8 g) andsulfuric acid (97 wt % by weight, 73.74 g) was added dropwise over 20minutes, with paying attention to an increase in temperature. After thecompletion of the dropwise addition, the reaction was performed withmaintaining at 95° C. for 100 minutes to obtain a reaction product.

The above reaction product was dissolved by introducing into 450 ml of atoluene/methyl isobutyl ketone (mixing ratio: 2/1) mixed solvent and theresulting resin mixed solution was washed with an aqueous 0.3 wt %sodium hydroxide solution to remove an acid and the unreacted phenol,and then concentrated by using an evaporator until the solventconcentration became 10% by weight, thereby to obtain a resin varnish.

Then, the resin varnish was poured into 5800 ml of n-hexane to removethe unreacted raw oil and to deposit a resin, which was filtered anddried to obtain 190 g of a highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 10, together with the reaction conditions.

EXAMPLE 32

100 g of a raw oil X and 263 g of phenol were charged into a 1 literglass reaction vessel, and the mixture was maintained at 40° C. whilestirring at a rate of 250 to 350 rpm. After the temperature becamestable, a mixture of formalin (aqueous 37 wt % solution) (164 g) andsulfuric acid (97 wt %, 74 g) was added dropwise over 20 minutes, withpaying attention to an increase in temperature. After the completion ofthe dropwise addition, the reaction was performed with maintaining at95° C. for 100 minutes to obtain a reaction product.

The above reaction product was dissolved in 300 ml of a toluene/methylisobutyl ketone (mixing ratio: 2/1) mixed solvent, and aqueous sulfuricacid was removed. The resulting resin mixed solution was transferred toa separating funnel to which 333 ml of distilled water was added, andthe solution was shaken and separated in an organic layer containing theunreacted oil, a resin solution layer and a water layer. Then, theorganic layer containing the unreacted oil and water layer were removed.

The resulting resin solution layer was washed with distilled water toremove an acid, and then the mixed solvent and unreacted phenol wereremoved by using an evaporator to obtain 335 g of a highly reactivemodified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 10, together with the reaction conditions.

EXAMPLES 33 TO 38

Curing accelerator-containing resin mixtures, compounds and moldedarticles were produced in the same manner as in Example 8, except thatthe highly reactive modified phenolic resin obtained in Examples 27 to32 and a phenolic novolak type epoxy resin (trade name EOCN-1020,manufactured by Nippon Kayaku Co., LTD.) were used.

The compositions, properties, etc. are shown in Table 11.

                                      TABLE 10                                    __________________________________________________________________________                Example                                                                            Example                                                                            Example                                                                            Example                                                                            Example                                                                            Example                                    27 28 29 30 31 32                                                           __________________________________________________________________________    Raw oil (g) 100  100  100  100  100  100                                        Phenol (g) 206 263 150 263 263 263                                            Formalin (g) 136 165 80 165 165 104                                           (37 wt %)                                                                     Acid catalyst (g) 62 73 37 74 74 74                                           Kind of acid -- sulfuric SK1B sulfuric sulfuric sulfuric sulfuric                                                 catalyst  acid  acid acid acid acid       Reaction (° C.) 95 120 95 95 95 95                                     temperature                                                                   Reaction time (min.) 120 280 106 120 120 100                                  Dropping mode -- sulfuric formalin sulfuric sulfuric sulfuric sulfuric                                              acid/  acid acid/ acid/ acid/                                                 formalin   formalin formalin                                               formalin                                   Yield (wt %) 236 203 178 212 100 341                                          (based on raw oil)                                                            Viscosity (p) 1.6 1.1 0.6 1.3 2.1 0.9                                         at 150° C.)                                                            (ICI viscometer)                                                              Number-average -- 413 367 295 382 458 396                                     molecular                                                                     weight (GPC)                                                                  Hydroxyl group (g/eq) 126 120 136 119 129 118                                 equivalent                                                                  __________________________________________________________________________

                                      TABLE 11                                    __________________________________________________________________________                             Ex. 33                                                                            Ex. 34                                                                            Ex. 35                                                                            Ex. 36                                                                            Ex. 37                                                                            Ex. 38                           __________________________________________________________________________    Modified phenolic                                                                         Example 27                                                                          pbw    9.48                                                   resin Example 28 pbw  9.20                                                     Example 29 pbw   9.93                                                         Example 30 pbw    9.15                                                        Example 31 pbw     9.52                                                       Example 32 pbw      9.10                                                     Epoxy resin EOCN1020 pbw 14.48 15.10 14.37 16.15 14.68 15.20                  Curing TPP pbw 0.25 0.25 0.25 0.25 0.25 0.25                                  accelerator                                                                   Fused silica CRS1102- pbw 75 75 75 75 75 75                                    GT200T                                                                       Carnauba wax  pbw 0.25 0.25 0.25 0.25 0.25 0.25                               Carbon black  pbw 0.20 0.20 0.20 0.20 0.20 0.20                               Gelation time  (170° C./SEC) 42 46 48 41 44 38                         Shore hardness immediately  -- 75 73 72 75 79 77                              after molding                                                                 Glass transition temperature  (° C.) 167 165 160 162 161 162                                                           (Tg)                          Flexural strength Room (kgf/mm.sup.2) 17.9 18.0 16.0 18.0 17.6 17.9                                                            temperature                  Flexural modulus Room (kgf/mm.sup.2) 1850 1900 1870 1850 1890 1900                                                             temperature                  Moisture 85° C./ (wt %) 0.25 0.23 0.22 0.25 0.26 0.25                  absorption rate 85%-72 hr                                                      85° C./ (wt %) 0.34 0.33 0.35 0.35 0.39 0.35                           85%-168 hr                                                                 __________________________________________________________________________     *pbw: parts by weight                                                    

EXAMPLE 39

100 g of the raw oil A obtained in the same manner as in Example 17,wherein a paraffin component and a component having low reactivity wereremoved, 114.4 g of phenol and 26.4 g of paraformaldehyde were chargedinto a 1 liter glass reaction vessel, and the mixture was maintained at40° C. while stirring at a rate of 250 to 350 rpm. After the temperaturebecame stable, 10 g of oxalic acid was added and the mixture was heatedto 140° C. over 30 minutes. After heating to 140° C., the reaction wasperformed with stirring at the same temperature for 90 minutes, toobtain a reaction product.

The above reaction product was dissolved by introducing into 190 ml of amixed solvent prepared by mixing toluene and acetone in a proportion of7:3, and the resulting resin mixed solution was washed by adding 140 mlof distilled water to remove an acid remained in the resin mixedsolution. The mixed solvent was removed from the resulting acid-removedresin mixed solution using an evaporator to obtain a crude highlyreactive modified phenolic resin.

Furthermore, the unreacted phenol remained in the resin was removed byblowing nitrogen into the resin at 155° C. for 30 minutes, to obtain158.3 g of a highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 12, together with the reaction conditions.

EXAMPLE 40

100 g of a raw oil A, 16.3 g of phenol, 2.6 g of paraformaldehyde and1.4 g of oxalic acid were charged into a 1 liter glass reaction vessel,and the mixture was heated to 140° C. while stirring at a rate of 250 to350 rpm over 30 minutes. After heating to 140° C., the reaction wasperformed with stirring at the same temperature for 90 minutes, toobtain a reaction product.

Then, the reaction product was allowed to stand and be cooled to roomtemperature and the unreacted raw oil separated in the upper layer wasremoved by decantation to obtain a crude highly reactive modifiedphenolic resin.

The unreacted phenol remained in the above crude highly reactivemodified phenolic resin was removed by blowing nitrogen into the resinat 155° C. for 30 minutes. Furthermore, the temperature was raised to180° C. under a nitrogen atmosphere and, after maintaining for 1 hour,the temperature was lowered to room temperature to obtain 26 g of ahighly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 12, together with the reaction conditions.

EXAMPLE 41

100 g of a raw oil A, 114.4 g of phenol and 18.5 g of paraformaldehydewere charged into a 1 liter glass reaction vessel, and the mixture wasmaintained at 40° C. while stirring at a rate of 250 to 350 rpm. Afterthe temperature became stable, 1.4 g of oxalic acid was added and themixture was heated to 100° C. over 15 minutes. After heating to 100° C.,1.4 g of oxalic acid was further added. Then, the temperature was raisedto 140° C. over 15 minutes and the reaction was performed for 90minutes, to obtain a reaction product.

The above reaction product was introduced into a heavy naphtha to removethe unreacted raw oil.

The unreacted phenol remained in the above crude highly reactivemodified phenolic resin thus obtained was removed by steam distillationat 155° C.. Then, the temperature was raised to 180° C. under a nitrogenatmosphere and, after maintaining for 1 hour, the temperature waslowered to room temperature to obtain 72 g of a highly reactive modifiedphenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 12, together with the reaction conditions.

EXAMPLE 42

100 g of a raw oil A, 62.4 g of phenol and 12 g of paraformaldehyde werecharged into a 1 liter glass reaction vessel, and the mixture wasmaintained at 40° C. while stirring at a rate of 250 to 350 rpm. Afterthe temperature became stable, 1.4 g of oxalic acid was added and themixture was heated to 140° C. over 30 minutes. After heating to 140° C.,the reaction was performed with stirring at the same temperature for 90minutes, to obtain a reaction product.

The above reaction product was purified in the same manner as in Example40 to obtain 35 g of a highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 12, together with the reaction conditions.

EXAMPLE 43

100 g of a raw oil B, 100 g of phenol, 19.7 g of paraformaldehyde and1.3 g of oxalic acid were charged into a 1 liter glass reaction vessel,and the mixture was heated to 140° C. while stirring at a rate of 250 to350 rpm over 30 minutes. After heating to 140° C., the reaction wasperformed with stirring at the same temperature for 90 minutes, toobtain a reaction product.

The above reaction product was allowed to stand and cooled to 50° C. andthe unreacted raw oil separated in the upper layer was removed bydecantation to obtain a crude highly reactive modified phenolic resin.

The above crude highly reactive modified phenolic resin was subjected tovacuum distillation until phenol is not distilled and, furthermore,nitrogen was blown at 155° C. to remove the unreacted phenol.

To the resin thus obtained, 100 ml of a heavy naphtha was added and themixture was stirred under reflux at 100° C. for 30 minutes to extractthe unreacted raw oil remained in the resin. Then, the heavy naphthacontaining the unreacted raw oil was removed by decantation to removethe unreacted raw oil remained in the resin, the temperature was furtherraised to 180° C. under a nitrogen atmosphere and, after maintaining for1 hour, the temperature was lowered to room temperature to obtain 71 gof a highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 12, together with the reaction conditions.

EXAMPLE 44

100 g of a raw oil B, 100 g of phenol and 1.4 g of oxalic acid werecharged into a 1 liter glass reaction vessel, and the mixture wasmaintained at 40° C. while stirring at a rate of 250 to 350 rpm. Afterthe temperature became stable, 7 g of paraformaldehyde was added andheating was started. After the temperature reached 70° C., 7 g ofparaformaldehyde was further added and the temperature was raised to 90°C. After the temperature reached 90° C., 5.7 g of paraformaldehyde and1.3 g of oxalic acid were added and the temperature was raised to 100°C., and then the reaction was performed while stirring at the sametemperature for 100 minutes, to obtain a reaction product.

The above reaction product was subjected to vacuum (40 mmHg)distillation until phenol was not distilled and, furthermore, nitrogenwas blown at 155° C. to remove the unreacted phenol.

The resin thus obtained was treated with a heavy naphtha to remove theunreacted raw oil remained in the resin, and the temperature was furtherraised to 180° C. under a nitrogen atmosphere. After maintaining for 1hour, the temperature was lowered to room temperature to obtain 76 g ofa highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 12, together with the reaction conditions.

EXAMPLE 45

100 g of a raw oil C, 121.6 g of phenol, 29.3 g of paraformaldehyde and1.3 g of oxalic acid were charged into a 1 liter glass reaction vessel,and the mixture was heated to 100° C. while stirring at a rate of 250 to350 rpm over 20 minutes. After heating to 100° C., the reaction wasperformed while stirring at the same temperature for 100 minutes, toobtain a reaction product.

The above reaction product was dissolved by adding 190 ml ofacetonitrile, and then 190 ml of a heavy naphtha was added to theresulting resin mixed solution to extract and remove the unreacted oilremained in the resin mixed solution.

The acetonitrile was removed from the resulting acid-removed resin mixedsolution by using an evaporator to obtain a crude highly reactivemodified phenolic resin.

The above crude highly reactive modified phenolic resin was subjected tovacuum distillation at 185° C. to remove the unreacted phenol and, aftermaintaining at the same temperature for 1 hour while blowing nitrogen,the temperature was lowered to room temperature to obtain 98 g of ahighly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 12, together with the reaction conditions.

EXAMPLE 46

100 g of a raw oil C, 121.6 g of o-cresol, 29.7 g of paraformaldehydeand 1.33 g of paratoluenesulfonic acid were charged into a 1 liter glassreaction vessel, and the mixture was heated to 100° C. over 20 minutes,while stirring at a rate of 250 to 350 rpm. After heating to 100° C.,the reaction was performed while stirring at the same temperature for100 minutes, to obtain a reaction product.

The above reaction product was dissolved by introducing into 190 ml ofmethyl isobutyl ketone, and then 140 ml of distilled water was added tothe resulting resin mixed solution to remove an acid remained in theresin mixed solution.

The resulting acid-removed resin mixed solution was concentrated byusing an evaporator until the resin concentration became 60% by weight,and the resulting resin solution was introduced into a heavy naphtha toremove the unreacted raw oil remained in the resin.

The unreacted o-cresol remained in the above crude highly reactivemodified phenolic resin was removed by blowing nitrogen into the resinat 155° C. for 30 minutes to obtain 123 g of a highly reactive modifiedphenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 12, together with the reaction conditions.

EXAMPLE 47

100 g of a raw oil D, 126.4 g of phenol, 20.4 g of paraformaldehyde and11.2 g of oxalic acid were charged into a 1 liter glass reaction vessel,and the mixture was heated to 160° C. over 30 minutes while stirring ata rate of 250 to 350 rpm. After heating to 160° C., the reaction wasperformed while stirring at the same temperature for 90 minutes, toobtain a reaction product.

The above reaction product was treated in the same manner in Example 46to obtain 88 g of a highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 12, together with the reaction conditions.

EXAMPLE 48

100 g of a raw oil E, 283.0 g of α-naphthol, 79.0 g of paraformaldehydeand 15.3 g of an acidic ion exchange resin Dia-ion SK1B (manufactured byMitsubishi Chemical Co., Ltd.) were charged into a 1 liter glassreaction vessel, and the mixture was heated to 100° C. over 20 minuteswhile stirring at a rate of 250 to 350 rpm.

After heating to 100° C., the reaction was performed while stirring atthe same temperature for 100 minutes, to obtain a reaction product.

The above reaction product was filtered by using a metal mesh of 60 meshto remove the used ion exchange resin, and then allowed to stand and becooled to room temperature. Then, the unreacted raw oil separated in theupper layer was removed by decantation to obtain a crude highly reactivemodified phenolic resin.

The above crude highly reactive modified phenolic resin was subjected tosteam distillation at 155° C. for 30 minutes and the unreactedα-naphthol remained in the resin was removed by further blowing nitrogenat the same temperature for 10 minutes to obtain 224 g of a highlyreactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 12, together with the reaction conditions.

EXAMPLE 49 TO 58

Curing accelerator-containing resin mixtures, compounds an moldedarticles were produced in the same manner as in Example 8, except thatthe highly reactive modified phenolic resins obtained in Examples 39 to48 and an ortho-cresol novolak type epoxy resin (trade name: EOCN1020,manufactured by Nippon Kayaku Co., Ltd) or a bisphenol type epoxy resin(YX-4000M) were used.

The compositions, properties, etc. are shown in Table 13.

                                      TABLE 12                                    __________________________________________________________________________                    Ex. 39                                                                            Ex. 40                                                                            Ex. 41                                                                            Ex. 42                                                                            Ex. 43                                                                            Ex. 44                                                                            Ex. 45                                                                            Ex. 46                                                                            Ex. 47                                                                            Ex. 48                    __________________________________________________________________________    Raw oil     (g) 100 100 100 100 100 100 100 100 100 100                         Kind of raw oil -- A* A A A B B C C D E                                     Phenols                                                                            phenol (g) 114.4                                                                             16.3                                                                              114.4                                                                             62.4                                                                              100.0                                                                             100.0                                                                             121.6                                                                             121.6                                                                             126.4                                                                             283.0                        o-Cresol                                                                      α-Naphthol                                                           Formaldehyde compound                                                                     (g) 26.4                                                                              2.6 18.5                                                                              12.0                                                                              19.7                                                                              19.7                                                                              29.3                                                                              29.7                                                                              20.4                                                                              79.0                        Acid catalyst (g) 10.0 1.4 2.8 1.4 1.3 2.7 1.3 1.3 11.2 15.3                  Kind of acid catalyst -- Oxalic Oxalic Oxalic Oxalic Oxalic Oxalic                                                              Oxalic PTS Oxalic                                                             SK1B                          acid acid acid acid acid acid acid  acid                                    Reaction temperature (° C.) 140 140 140 140 140 100 100 100 160                                                          100                         Reaction time (min.) 120 120 120 120 120 110 120 120 120 360                  Yield (based on raw oil) (wt %) 158.3 26 72 35 71 76 98 123 88 224                                                               Viscosity at                                                                 150° C.) (p)                                                           2.5 10 or 0.7 2.3 1.3                                                         2.0 4.9 8.4 0.6 10.0                                                           (ICI viscometer)                                                             more                        Number-average molecular -- 707 650 538 644 684 659 843 959 503 926                                                              weight                     Hydroxy group equivalent (g/eq) 127 175 132 141 132 128 129 139 131         __________________________________________________________________________                                                        152                        A*: Free from paraffin                                                   

                                      TABLE 13                                    __________________________________________________________________________                             Ex. 49                                                                            Ex. 50                                                                            Ex. 51                                                                            Ex. 52                                                                            Ex. 53                               __________________________________________________________________________      Modified phenolic Example 39 pbw 9.53                                         resin Example 40 pbw  11.42                                                    Example 41 pbw   9.72                                                         Example 42 pbw    10.11                                                       Example 43 pbw     9.72                                                       Example 44 pbw                                                                Example 45 pbw                                                                Example 46 pbw                                                                Example 47 pbw                                                                Example 48 pbw                                                               Epoxy resin YX-4000H pbw   14.34 13.95                                         EOCN-1020 pbw 14.77 12.88                                                    Curing TPP pbw 0.25 0.25 0.49 0.49 0.49                                       accelerator                                                                   Fused silica CRS1102- pbw 75 75 75 75 75                                       GT200T                                                                       Carnauba wax  pbw 0.25 0.25 0.25 0.25 0.25                                    Carbon black  pbw 0.20 0.20 0.20 0.20 0.20                                    Gelation time  (170° C./SEC) 38 40 39 40 41                            Shore hardness immediately  -- 88 83 75 73 73                                 after molding                                                                 Glass transition temperature  (° C.) 176 169 142 142 143                                                       (Tg)                                  Flexural strength Room (kgf/mm.sup.2) 17.9 17.5 15.9 16.7 17.7                 temperature                                                                  Flexural modulus Room (kgf/mm.sup.2) 1890 1870 1840 1850 1870                  temperature                                                                  Moisture 85° C./ (wt %) 0.25 0.23 0.26 0.24 0.25                       absorption rate 85%-72 hr                                                      85° C./ (wt %) 0.34 0.31 0.36 0.33 0.33                                85%-168 hr                                                                 __________________________________________________________________________         Ex. 54 Ex. 55 Ex. 56 Ex. 57 Ex. 58                                       __________________________________________________________________________      Modified phenolic Example 39 pbw                                              resin Example 40 pbw                                                           Example 41 pbw                                                                Example 42 pbw                                                                Example 43 pbw                                                                Example 44 pbw 9.57                                                           Example 45 pbw  9.62                                                          Example 46 pbw   10.13                                                        Example 47 pbw    9.67                                                        Example 48 pbw     10.54                                                     Epoxy resin YX-4000H pbw    14.39 13.52                                        EOCN-1020 pbw 14.73 14.68 14.17                                              Curing TPP pbw 0.25 0.25 0.25 0.49 0.49                                       accelerator                                                                   Fused silica CRS1102- pbw 75 75 75 75 75                                       GT200T                                                                       Carnauba wax  pbw 0.25 0.25 0.25 0.25 0.25                                    Carbon black  pbw 0.20 0.20 0.20 0.20 0.20                                    Gelation time  (170° C./SEC) 38 38 35 39 41                            Shore hardness immediately  -- 89 88 90 75 74                                 after molding                                                                 Glass transition temperature  (° C.) 173 171 172 145 147                                                       (Tg)                                  Flexural strength Room (kgf/mm.sup.2) 18.3 18.4 18.7 17.9 18.0                 temperature                                                                  Flexural modulus Room (kgf/mm.sup.2) 1900 1910 1920 1870 1880                  temperature                                                                  Moisture 85° C./ (wt %) 0.25 0.25 0.23 0.24 0.19                       absorption rate 85%-72 hr                                                      85° C./ (wt %) 0.32 0.32 0.31 0.33 0.29                                85%-168 hr                                                                 __________________________________________________________________________     *pbw: parts by weight                                                    

EXAMPLE 59

100 g of a petroleum raw oil B. 94 g of phenol, 18.5 g ofparaformaldehyde and 2.5 g of oxalic acid were charged into a 1 literglass reaction vessel, and the mixture was maintained at 40° C. whilestirring at a rate of 250 to 350 rpm and heated to 140° C. over 30minutes. Then, the reaction was performed while maintaining at the sametemperature for 90 minutes, to obtain a reaction product.

The above reaction product was dissolved by introducing into 161 ml ofmethyl isobutyl ketone and the resulting resin mixed solution was washedwith distilled water to remove an acid. Then, the mixed solvent wasremoved by using an evaporator to obtain 160 g of a crude highlyreactive modified phenolic resin.

To the resulting crude highly reactive modified phenolic resin, 160 mlof a heavy naphtha was added and the mixture was heated to about 98° C.and stirred for 30 minutes. After cooling to room temperature, the heavynaphtha layer containing the unreacted oil, which was separated as theupper layer, was removed by decantation. A series of unreacted oilextraction removing operations using the heavy naphtha were performedone more time under the same conditions.

Then, the unreacted phenol was removed by dissolving the resin layer asthe lower layer at about 150° C. and blowing nitrogen to obtain 65 g ofa highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 14, together with the reaction conditions.

EXAMPLE 60

The highly reactive modified phenolic resin was obtained in the samemanner as in Example 59, except that the reaction conditions werechanged as shown in Table 14, and the reaction product was dissolved in182 ml of methyl isobutyl ketone, to obtain 167 g of a crude highlyreactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 14, together with the reaction conditions.

EXAMPLE 61

100 g of a petroleum raw oil B, 114 g of phenol, 18.5 g ofparaformaldehyde and 2.8 g of oxalic acid were charged into a 1 literglass reaction vessel, and the mixture was maintained at 40° C. whilestirring at a rate of 250 to 350 rpm and heated to 140° C. over 30minutes. Then, the reaction was performed while maintaining at the sametemperature for 90 minutes, to obtain a reaction product.

The above reaction product was dissolved by introducing into 182 ml of amixed solvent of methyl isobutyl ketone and toluene (7:1) and theresulting resin mixed solution was washed with distilled water to removean acid. Then, the mixed solvent was removed by using an evaporator toobtain 175 g of a crude highly reactive modified phenolic resin.

To the resulting highly reactive crude modified phenolic resin, 350 mlof n-heptane was added and the mixture was heated to about 85° C. andstirred for 30 minutes. After cooling to room temperature, the n-heptanelayer containing the unreacted oil, which was separated as the upperlayer, was removed by decantation.

Then, the unreacted phenol was removed by dissolving the resin layer asthe lower layer at about 150° C., followed by steam distillation toobtain 77 g of a highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 14, together with the reaction conditions.

EXAMPLE 62

The highly reactive modified phenolic resin was obtained in the samemanner as in Example 59, except that the reaction conditions werechanged as shown in Table 14, the heated mixture of 160 g of theobtained crude modified phenolic resin with the heavy naphtha was cooledto 80 ° C., and unreacted phenol was removed by steam distillation.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 14, together with the reaction conditions.

EXAMPLE 63

100 g of a petroleum raw oil X, 122 g of phenol, 25.4 g ofparaformaldehyde and 1.3 g of oxalic acid were charged in a 1 literglass reaction vessel, and the mixture was maintained at 40° C. whilestirring at a rate of 250 to 350 rpm and heated to 100° C. over 30minutes. Then, the reaction was performed while maintaining at the sametemperature for 90 minutes, to obtain a reaction product.

The above reaction product was dissolved by introducing into 180 ml of amixed solvent of methyl isobutyl ketone and toluene (7:3) and theresulting resin mixed solution was washed with distilled water to removean acid. Then, the mixed solvent was removed by using an evaporator toobtain 200 g of a crude highly reactive modified phenolic resin.

To the resulting crude highly reactive modified phenolic resin, 400 mlof n-octane was added and the mixture was heated to about 90° C. andstirred for 30 minutes. After cooling to 80° C., the n-octane layercontaining the unreacted oil, which was separated as the upper layer bystanding at the same temperature, was removed by decantation.

Then, the unreacted phenol was removed by dissolving the resin layer asthe lower layer at about 150° C. and blowing nitrogen to obtain 92 g ofa highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 14, together with the reaction conditions.

EXAMPLE 64

100 g of a coal raw oil S, 100 g of phenol, 19.7 g of paraformaldehydeand 1.3 g of oxalic acid were charged into a 1 liter glass reactionvessel, and the mixture was maintained at 40° C. while stirring at arate of 250 to 350 rpm and heated to 140° C. over 30 minutes. Then, thereaction was performed while maintaining at the same temperature for 90minutes, to obtain a reaction product.

The above reaction product was dissolved by introducing into 161 ml ofmethyl isobutyl ketone and the resulting resin mixed solution was washedwith distilled water to remove an acid. Then, the mixed solvent wasremoved by using an evaporator to obtain 160 g of a highly reactivecrude modified phenolic resin.

To the resulting crude highly reactive modified phenolic resin, 320 mlof a heavy naphtha was added and the mixture was heated to about 98° C.and stirred for 30 minutes. After cooling to 80° C., the heavy naphthalayer containing the unreacted oil, which was separated as the upperlayer by standing at the same temperature, was removed by decantation.

Then, the unreacted phenol was removed by dissolving the resin layer asthe lower layer at about 150° C., followed by steam distillation toobtain 51 g of a highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 14, together with the reaction conditions.

EXAMPLE 65

The highly reactive modified phenolic resin was obtained in the samemanner as in Example 59, except that the reaction conditions werechanged as shown in Table 14, the reaction product was dissolved in 170ml of methyl isobutyl ketone, to obtain 169 g of a crude phenolic resin,and the heated mixture of the crude phenolic resin with the kerosene wascooled to 80 ° C.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 14, together with the reaction conditions.

EXAMPLE 66

100 g of a petroleum raw oil B, 114 g of o-cresol, 18.5 g ofparaformaldehyde and 2.8 g of oxalic acid were charged into a 1 literglass reaction vessel, and the mixture was maintained at 40° C. whilestirring at a rate of 250 to 350 rpm and heated to 140° C. over 30minutes. Then, the reaction was performed while maintaining at the sametemperature for 90 minutes, to obtain a reaction product.

The above reaction product was dissolved by introducing into 190 ml of amixed solvent of toluene and acetone (7:3) and the resulting resin mixedsolution was washed with distilled water to remove an acid. Then, themixed solvent was removed by using an evaporator to obtain 174 g of acrude highly reactive modified phenolic resin.

To the resulting highly reactive crude modified phenolic resin, 350 mlof a heavy naphtha was added and the mixture was heated to about 98° C.and stirred for 30 minutes. After cooling to 80° C., the heavy naphthalayer containing the unreacted oil, which was separated as the upperlayer by standing at the same temperature, was removed by decantation.

Then, the unreacted o-cresol was removed by dissolving the resin layeras the lower layer at about 150° C., followed by steam distillation toobtain 79 g of a highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 14, together with the reaction conditions.

EXAMPLE 67

The highly reactivie modified phenolic resin was obtained in the samemanner as in Example 66, except that the reaction conditions werechanged as shown in Table 14, the reaction product was dissolved in 200ml of the mixed solvent, to obtain 197 g of a crude phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 14, together with the reaction conditions.

COMPARATIVE EXAMPLE 1

100 g of a petroleum raw oil B, 94 g of phenol, 18.5 g ofparaformaldehyde and 2.5 g of oxalic acid were charged into a 1 literglass reaction vessel, and the mixture was maintained at 40° C. whilestirring at a rate of 250 to 350 rpm and heated to 140° C. over 30minutes. Then, the reaction was performed while maintaining at the sametemperature for 90 minutes, to obtain a reaction product.

The above reaction product was dissolved by introducing 161 ml of methylisobutyl ketone, and the resulting resin mixed solution was washed withdistilled water to remove an acid and the mixed solvent was removed byusing an evaporator. Then, the unreacted phenol was removed by steamdistillation and water was further removed by blowing nitrogen to obtain148 g of a crude highly reactive modified phenolic resin.

Then, the crude highly reactive modified phenolic resin in theheat-molten state was poured into 3200 ml of a heavy naphtha of atemperature of about 10° C. to dissolve the unreacted oil into the heavynaphtha and to deposit the resin. The resulting resin was filtered anddried to obtain 78 g of a highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 14, together with the reaction conditions.

                                      TABLE 14                                    __________________________________________________________________________                      Ex. 59                                                                            Ex. 60                                                                             Ex. 61                                                                             Ex. 62                                                                             Ex. 63                                   __________________________________________________________________________    Reaction conditions                                                           Raw oil                                                                            Petroleum                                                                           (g)    100 100  100  --   --                                          raw oil B                                                                     Petroleum (g) --  --  --  100 100                                             raw oil X                                                                     Coal tar S (g) -- -- -- --  --                                               Phenols Phenol (g) 94 114 114 100 122                                          o-cresol (g) --  --  --  --  --                                               β-naphthol (g) -- -- -- -- --                                         Paraformaldehyde                                                                         (g)    18.5                                                                              18.5 18.5 19.7 25.4                                       Acid catalyst (g) 2.5 10 2.8 2.7 1.3                                          Reaction temperature (° C.) 140 140 140 100 100                        Reaction time (min.) 120 120 120 120 120                                    Extraction conditions                                                         Used solvent                                                                             --     Heavy                                                                             Heavy                                                                              n-heptane                                                                          Heavy                                                                              n-octane                                     naphtha naphtha  naphtha                                                    Amount of solvent (ml/Extraction 160 167 350 160 400                           times)                                                                       Stirring (° C.) 98 80 85 98 90                                         temperature                                                                   Stirring time (min.) 30 30 30 30 30                                           Number of extraction (times) 2 2 1 2 1                                      Properties                                                                    Yield (based on raw oil)                                                                 % by weight                                                                          65  73   77   76   92                                         Retention of (%) 0.9 1.1 1.3 1.2 1.3                                          unreacted product                                                             Viscosity at 150° C.) (p) 1.3 0.9 1.0 2.0 3.8                          (ICI viscometer)                                                              Number-average -- 713 634 629 659 818                                         molecular weight                                                              Hydroxyl group (g/equivalent) 133 129 130 128 130                             equivalent                                                                  Heating                                                                            (105° C.)                                                                    % by weight                                                                          0.09                                                                              0.05 0.08 0.11 0.09                                       weight (150° C.) % by weight 0.57 0.40 0.44 0.51 0.50                  loss                                                                        __________________________________________________________________________                                         Comp.                                      Ex. 64 Ex. 65 Ex. 66 Ex. 67 Ex. 1                                           __________________________________________________________________________    Reaction conditions                                                           Raw oil                                                                            Petroleum                                                                           (g)    --  100  100  100  100                                         raw oil B                                                                     Petroleum (g) -- --  --  --  --                                               raw oil X                                                                     Coal tar S (g) 100 -- --  --                                                 Phenols Phenol (g) 100 94 -- -- 94                                             o-cresol (g) --  --  114 -- --                                                β-naphthol (g) -- -- --  100 --                                       Paraformaldehyde                                                                         (g)    19.7                                                                              18.5 18.5 19.7 18.5                                       Acid catalyst (g) 1.3 2.5 2.8 2.7 2.5                                         Reaction temperature (° C.) 140 100 140 140 140                        Reaction time (min.) 120 120 120 120 120                                    Extraction conditions                                                         Used solvent                                                                             --     Heavy                                                                             Kerosene                                                                           Heavy                                                                              Heavy                                                                              Heavy                                        naphtha  naphtha naphtha naphtha                                            Amount of solvent (ml/Extruction 320 320 350 400 3200                          times)                                                                       Stirring (° C.) 98 98 98 98 --                                         temperature                                                                   Stirring time (min.) 30 30 30 30 --                                           Number of extraction (times) 1 1 1 1 --                                     Properties                                                                    Yield (based on raw oil)                                                                 % by weight                                                                          51  69   79   84   78                                         Retention of (%) 1.0 1.1 1.1 1.4 10.3                                         unreacted product                                                             Viscosity at 150° C.) (p) 1.5 1.2 1.1 4.5 0.7                          (ICI viscometer)                                                              Number-average -- 695 697 725 1024 439                                        molecular weight                                                              Hydroxyl group (g/equivalent) 135 129 135 145 141                             equivalent                                                                  Heating                                                                            (105° C.)                                                                    % by weight                                                                          0.12                                                                              0.11 0.07 0.12 2.09                                       weight (150° C.) % by weight 0.51 0.42 0.44 0.52 4.21                  loss                                                                        __________________________________________________________________________     *pbw: parts by weight                                                    

EXAMPLE 68

100 g (0.72 mol) of a raw oil P, 38.2 g (0.41 mol) of phenol and 9.1 g(0.30 mol) of paraformaldehyde were charged into a 1 liter glassreaction vessel, and the mixture was maintained at 40° C. while stirringat a rate of 250 to 350 rpm. After the temperature became stable, 1.5 g(0.012 mol) of oxalic acid was added. The mixture was heated to 140° C.over 30 minutes and the reaction was continued while stirring at thesame temperature for 90 minutes to obtain a polycondensation reactionmixture.

To the reaction mixture, 120 ml of methyl isobutyl ketone was added toform a resin mixed solution. The resulting resin mixed solution waswashed with 82 ml of distilled water to remove an acid remained in theresin mixed solution.

The resulting acid-removed resin mixed solution was concentrated byusing an evaporator until the resin concentration became 60% by weight,and then introduced into a heavy naphtha to remove the unreacted raw oilremained in the resin solution.

The resulting crude highly reactive modified phenolic resin wassubjected to vacuum distillation until phenol was not distilled from theresin, and then nitrogen was blown into the crude highly reactivemodified phenolic resin at 155° C. after the removal of phenol to obtain55.3 g of a highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 15, together with the reaction conditions.

EXAMPLE 69

100 g (0.72 mol) of a raw oil P, 115.1 g (1.22 mol) of phenol and 18.9 g(0.63 mol) of paraformaldehyde, 1.5 g (0.012 mol) of oxalic acid werecharged into a 1 liter glass reaction vessel, and the mixture wasmaintained at 40° C. while stirring at a rate of 250 to 350 rpm. Afterthe temperature became stable, 1.5 g (0.012 mol) of oxalic acid wasfurther added. The mixture was heated to 100° C. over 20 minutes and thereaction was continued while stirring at the same temperature for 220minutes to obtain a polycondensation reaction mixture.

The above reaction mixture was poured into a heavy naphtha to remove theunreacted raw material, thereby obtaining a crude highly reactivemodified phenolic resin.

Nitrogen was blown into this crude highly reactive modified phenolicresin at 155° C. for 30 minutes to remove the unreacted phenol remainedin the resin.

Then, the crude highly reactive modified phenolic resin after removingphenol was heated to 180° C. under a nitrogen atmosphere and, aftermaintaining for 1 hour, the resin was cooled to room temperature toobtain 83 g of a highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 15, together with the reaction conditions

EXAMPLE 70

100 g (0.72 mol) of a raw oil P, 62.4 g (0.66 mol) of phenol and 12.0 g(0.63 mol) of paraformaldehyde were charged into a 1 liter glassreaction vessel, and the mixture was maintained at 40° C. while stirringat a rate of 250 to 350 rpm. After the temperature became stable, 0.75 g(0.006 mol) of oxalic acid was added. The mixture was heated to 90° C.over 20 minutes. Then, 0.75 g (0.006 mol) of oxalic acid was added, themixture was heated to 100° C. over 10 minutes and the reaction wascontinued while stirring at the same temperature for 90 minutes toobtain a polycondensation reaction mixture.

The reaction mixture was poured into a heavy naphtha, followed byheating with stirring to remove the unreacted raw material, therebyobtaining a crude highly reactive modified phenolic resin.

The resulting crude highly reactive modified phenolic resin wassubjected to steam distillation at 155° C. to remove the unreactedphenol remained in the resin.

Then, the crude highly reactive modified phenolic resin after removingphenol was heated to 180° C. under a nitrogen atmosphere and, aftermaintaining at the same temperature for 1 hour, the resin was cooled toroom temperature to obtain 81.2 g of a highly reactive modified phenolicresin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 15, together with the reaction conditions.

EXAMPLE 71

100 g (0.68 mol) of a raw oil Q, 102.2 g (1.09 mol) of phenol and 19.6 g(0.65 mol) of paraformaldehyde were charged into a 1 liter glassreaction vessel, and the mixture was maintained at 40° C. while stirringat a rate of 250 to 350 rpm. After the temperature became stable, 1.6 g(0.013 mol) of oxalic acid was added. The mixture was heated to 100° C.over 20 minutes and the reaction was continued while stirring at thesame temperature for 100 minutes to obtain a polycondensation reactionmixture.

To this reaction mixture, 170 ml of methanol was added to form a resinmixed solution. 170 ml of a heavy naphtha was added to the resultingresin mixed solution to remove the unreacted raw material remained inthe resin mixed solution.

Then, methanol was distilled off from the resin mixed solution by usingan evaporator to obtain a crude highly reactive modified phenolic resin.Nitrogen was blown into the resulting crude highly reactive modifiedphenolic resin at 155° C. for 30 minutes to remove the unreacted phenolremained in the resin.

Then, the crude highly reactive modified phenolic resin after re-movingphenol was heated to 180° C. under a nitrogen atmosphere and, aftermaintaining at the same temperature for 1 hour, the resin was cooled toroom temperature to obtain 125.6 g of a highly reactive modifiedphenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 15, together with the reaction conditions.

EXAMPLE 72

100 g (0.68 mol) of a raw oil Q, 102.2 g (1.09 mol) of phenol, 19.6 g(0.65 mol) of paraformaldehyde and 3.2 g (0.025 mol) of oxalic acid werecharged into a 1 liter glass reaction vessel, and the mixture was heatedto 100° C. over 20 minutes while stirring at a rate of 250 to 350 rpm.Then, the reaction was continued while stirring at the same temperaturefor 100 minutes to obtain a polycondensation reaction mixture.

To the reaction mixture, 120 ml of methyl isobutyl ketone was added toform a resin mixed solution. The resulting resin mixed solution waswashed with 82 ml of distilled water to remove an acid remained in theresin mixed solution.

Methyl isobutyl ketone was distilled off from the resulting acid-removedresin mixed solution by using an evaporator, and then 170 ml ofacetonitrile was added to form a resin mixed solution again. To theresulting resin mixed solution, 170 ml of a heavy naphtha was added toremove the unreacted raw material remained in the resin mixed solution.

After acetonitrile was removed from this resin mixed solution by usingan evaporator, the vacuum distillation was performed until phenol wasnot distilled to obtain a crude highly reactive modified phenolic resin.

The remained phenol was removed by blowing nitrogen into the resultingcrude highly reactive modified phenolic resin at 55° C. to obtain 131.0g of a highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 15, together with the reaction conditions.

EXAMPLE 73

100 g (0.68 mol) of a raw oil Q, 110.5 g (1.18 mol) of phenol and 0.8 g(0.06 mol) of oxalic acid were charged in a 1 liter glass reactionvessel, and the mixture was maintained at 40° C. while stirring at arate of 250 to 350 rpm. After the temperature became stable, 8.5 g (0.28mol) of paraformaldehyde was added and heating was started. After thetemperature reached 70° C., 8.0 g (0.27 mol) of paraformaldehyde wasfurther added and the temperature was raised to 90° C. After thetemperature reached 90° C., 8.0 g (0.27 mol) of paraformaldehyde and 0.8g (0.06 mol) of oxalic acid were added, the temperature was raised to100° C., and then the reaction was continued while stirring at the sametemperature for 100 minutes to obtain a reaction mixture.

The above reaction mixture was subjected to vacuum distillation untilphenol was not distilled, and the unreacted phenol was removed byfurther blowing nitrogen at 155° C. to obtain a crude highly reactivemodified phenolic resin.

The resulting crude highly reactive modified phenolic resin wasintroduced into a heavy naphtha to remove the unreacted raw materialremained in the resin.

Then, the crude highly reactive modified phenolic resin after removingthe unreacted raw material was heated to 180° C. under a nitrogenatmosphere and, after maintaining at the same temperature for 1 hour,the resin was cooled to room temperature to obtain 121 g of a highlyreactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 15, together with the reaction conditions.

EXAMPLE 74

100 g (0.61 mol) of a raw oil R, 108.6 g (1.16 mol) of phenol, 15.6 g(0.52 mol) of paraformaldehyde and 1.6 g (0.013 mol) of oxalic acid werecharged into a 1 liter glass reaction vessel, and the mixture was heatedto 100° C. over 20 minutes while stirring at a rate of 250 to 350 rpm.Then, the reaction was continued while stirring at the same temperaturefor 100 minutes to obtain a polycondensation reaction mixture.

170 ml of acetonitrile was introduced into the above reaction mixture toform a resin mixed solution, and then 170 ml of a heavy naphtha wasadded to the resulting resin mixed solution to remove the unreacted rawmaterial remained in the resin mixed solution.

Acetonitrile was distilled off from the resulting resin mixed solutionby using an evaporator to obtain a crude highly reactive modifiedphenolic resin.

Nitrogen was blown into the crude highly reactive modified phenolicresin at 155° C. for 30 minutes to remove the unreacted phenol remainedin the resin.

Then, the crude highly reactive modified phenolic resin after removingphenol was heated to 180° C. under a nitrogen atmosphere and, aftermaintaining at the same temperature for 1 hour, the resin was cooled toroom temperature to obtain 121 g of a highly reactive modified phenolicresin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 15, together with the reaction conditions.

EXAMPLE 75

100 g (0.61 mol) of a raw oil R, 125.4 g (1.33 mol) of phenol, 24 g(0.80 mol) of paraformaldehyde, 70.7 g of m-xylene and 1.6 g (0.008 mol)of paratoluenesulfonic acid were charged into a 1 liter glass reactionvessel, and the mixture was heated to 100° C. over 20 minutes whilestirring at a rate of 250 to 350 rpm. Then, the reaction was continuedwhile stirring at the same temperature for 100 minutes to obtain apolycondensation reaction mixture.

To this reaction mixture, 180 ml of methyl isobutyl ketone was added toform a resin mixed solution, and the resulting resin mixed solution waswashed with 120 ml of distilled water to remove an acid remained in theresin.

The resulting acid-removed resin mixed solution was subjected to vacuumdistillation until the unreacted phenol remained in methyl isobutylketone and resin was not distilled, and nitrogen was further blown at155° C. to obtain a crude highly reactive modified phenolic resin.

The unreacted raw material remained in the highly reactive modifiedphenolic resin after removing phenol was removed by introducing theresin into a heavy naphtha, followed by heating with stirring to obtain108 g of a highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 15, together with the reaction conditions.

EXAMPLE 76

100 g (0.61 mol) of a raw oil R, 45 g (0.48 mol) of phenol, 10 g (0.33mol) of paraformaldehyde and 10 g (0.063 mol) of oxalic acid werecharged into a 1 liter glass reaction vessel, and the mixture was heatedto 100° C. over 20 minutes while stirring at a rate of 250 to 350 rpm.Then, the reaction was continued while stirring at the same temperaturefor 100 minutes to obtain a polycondensation reaction mixture.

The unreacted phenol remained in the resin was removed by blowingnitrogen into the above reaction mixture at 155° C. over 30 minutes toobtain a crude highly reactive modified phenolic resin.

To the crude highly reactive modified phenolic resin after removingphenol, 170 ml of dimethyl sulfoxide was added to form a resin mixedsolution. To the resulting resin mixed solution, 170 ml of a heavynaphtha was added to remove the unreacted raw material remained in theresin mixed solution.

Then, the resin mixed solution was subjected to vacuum distillationuntil dimethyl sulfoxide was not distilled and heated to 180° C. under anitrogen atmosphere. After maintaining at the same temperature for 1hour, the resulting solution was cooled to room temperature to obtain 55g of a highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 15, together with the reaction conditions.

EXAMPLE 77

100 g (0.61 mol) of a raw oil R, 263 g (2.80 mol) of phenol, 63 g (2.10mol) of paraformaldehyde and 18.8 g of an acidic ion exchange resinDaiya-ion SK1B (manufactured by Mitsubishi Chemical Co., Ltd.) werecharged in a 1 liter glass reaction vessel, and the mixture was heatedto 100° C. over 20 minutes while stirring at a rate of 250 to 350 rpm.Then, the reaction was continued while stirring at the same temperaturefor 100 minutes to obtain a polycondensation reaction mixture.

To the reaction mixture, 340 ml of methyl isobutyl ketone was added toform a resin mixed solution. The resulting resin mixed solution wasfiltered by using a metal mesh of 60 mesh to remove the used ionexchange resin.

The resulting acid-removed resin mixed solution was concentrated byusing an evaporator until the resin concentration became 60% by weight,and then introduced into a heavy naphtha to remove the unreacted rawmaterial remained in the resin.

Then, the resulting crude highly reactive modified phenolic resin wassubjected to vacuum distillation until the remained unreacted phenol wasnot distilled and nitrogen was further blown at 155° C. to obtain 143 gof a highly reactive modified phenolic resin.

Properties of the resulting highly reactive modified phenolic resin areshown in Table 15, together with the reaction conditions.

EXAMPLES 78 TO 87

Curing accelerator-containing resin mixtures, compounds and moldedarticles were produced in the same manner as in Example 8, except thatthe highly reactive modified phenolic resins obtained in Examples 68 to77 and an epoxy resin (trade name: EOCN1020 YX-4000H) were used.

The compositions, properties, etc. are shown in Table 16.

                                      TABLE 15                                    __________________________________________________________________________                         Ex. 68                                                                            Ex. 69                                                                             Ex. 70                                                                            Ex. 71                                                                            Ex. 72                                                                            Ex. 73                                                                            Ex. 74                                                                            Ex. 75                                                                            Ex. 76                                                                            Ex. 77              __________________________________________________________________________    Kind of raw material                                                                          --   Raw oil                                                                           Raw oil                                                                            Raw oil                                                                           Raw oil                                                                           Raw oil                                                                           Raw oil                                                                           Raw oil                                                                           Raw oil                                                                           Raw oil                                                                           Raw oil                                                                          P P P Q Q Q                                                                R R R R                                                                        Raw material                                                                 (g) 100.0 100.0                                                               00.0 100.0                                                                    100.0 100.0                                                                   100.0 100.0                                                                   100.0 100.0                                                                    Phenol (g)                                                                   38.2 115.1 62.4                                                               102.2 102.2                                                                   110.5 108.6                                                                   125.4 45.0                                                                    263.0                 Formaldehyde compound (g) 9.1 18.9 12.0 19.6 19.6 24.5 15.6 24.0 10.0                                                                 63.0                  Aromatic hydrocarbon compound (g) --  --  --  --  --  --  --  70.7 --                                                                 --                    Acid catalyst (g) 1.5 3.0 1.5 1.6 3.2 1.6 1.6 1.6 8.0 18.8                    Kind of acid -- Oxalic Oxalic Oxalic Oxalic Oxalic Oxalic Oxalic PTS                                                                  Oxalic Solid                                                                   catalyst  acid                                                               acid acid acid                                                                acid acid acid                                                                acid acid                                                                      Reaction                                                                     temperature                                                                   (° C.)                                                                 140 100 100 100                                                               00 100 100 100                                                                100 100                                                                        Reaction time                                                                (min.) 120 240                                                                120 120 120 120                                                               120 120 120 120       Yield (based on raw oil) (wt %) 55.3 83.0 81.2 125.6 131.0 121.0 121.0                                                                108.0 55.0                                                                    143.0                 Hydroxy group equivalent (g/eq) 170 140 138 140 144 138 135 128 133 196       Viscosity at 150° C.) (p) 9.5 0.4 1.9 2.6 2.7 2.5 0.2 4.0 8.0                                                                  9.6                   (ICI Viscometer)                                                              Number-average molecular weight -- 810 720 715 730 726 701 681 727 773                                                                803                 __________________________________________________________________________

                                      TABLE 16                                    __________________________________________________________________________                             Ex. 78                                                                            Ex. 79                                                                            Ex. 80                                                                            Ex. 81                                                                            Ex. 82                               __________________________________________________________________________      Modified phenolic Example 68 pbw 11.25                                        resin Example 69 pbw  10.09                                                    Example 70 pbw   9.97                                                         Example 71 pbw    10.06                                                       Example 72 pbw     10.22                                                      Example 73 pbw                                                                Example 74 pbw                                                                Example 75 pbw                                                                Example 76 pbw                                                                Example 77 pbw                                                               Epoxy resin YX-4000H pbw   14.09 14.00 13.84                                   EOCN-1020 pbw 13.05 14.21                                                    Curing TPP pbw 0.25 0.25 0.49 0.49 0.49                                       accelerator                                                                   Fused silica CRS1102- pbw 75.00 75.00 75.00 75.00 75.00                        GT200T                                                                       Carnauba wax  pbw 0.25 0.25 0.25 0.25 0.25                                    Carbon black  pbw 0.20 0.20 0.20 0.20 0.20                                    Gelation time  (170° C./SEC) 47 42 39 41 43                            Shore hardness immediately  -- 74 72 75 76 78                                 after molding                                                                 Glass transition temperature  (° C.) 165 158 160 162 160                                                       (Tg)                                  Flexural strength Room (kgf/mm.sup.2) 16.8 15.9 16.1 16.5 17.2                 temperature                                                                  Flexural modulus Room (kgf/mm.sup.2) 1850 1820 1830 1850 1880                  temperature                                                                  Moisture 85° C./ (wt %) 0.26 0.25 0.27 0.28 0.25                       absorption rate 85%-72 hr                                                      85° C./ (wt %) 0.38 0.35 0.39 0.40 0.34                                85%-168 hr                                                                 __________________________________________________________________________         Ex. 83 Ex. 84 Ex. 85 Ex. 86 Ex. 87                                       __________________________________________________________________________      Modified phenolic Example 68 pbw                                              resin Example 69 pbw                                                           Example 70 pbw                                                                Example 71 pbw                                                                Example 72 pbw                                                                Example 73 pbw 10.01                                                          Example 74 pbw  9.88                                                          Example 75 pbw   9.57                                                         Example 76 pbw    9.76                                                        Example 77 pbw     12.06                                                     Epoxy resin YX-4000H pbw    14.30 12.00                                        EOCN-1020 pbw 14.29 14.42 14.73                                              Curing TPP pbw 0.25 0.25 0.25 0.49 0.49                                       accelerator                                                                   Fused silica CRS1102- pbw 75.00 75.00 75.00 75.00 75.00                        GT200T                                                                       Carnauba wax  pbw 0.25 0.25 0.25 0.25 0.25                                    Carbon black  pbw 0.20 0.20 0.20 0.20 0.20                                    Gelation time  (170° C./SEC) 38 38 36 38 50                            Shore hardness immediately  -- 73 76 75 77 75                                 after molding                                                                 Glass transition temperature  (° C.) 162 156 161 165 166                                                       (Tg)                                  Flexural strength Room (kgf/mm.sup.2) 17.4 15.7 16.3 17.1 17.3                 temperature                                                                  Flexural modulus Room (kgf/mm.sup.2) 1890 1820 1850 1860 1880                  temperature                                                                  Moisture 85° C./ (wt %) 0.25 0.26 0.27 0.27 0.25                       absorption rate 85%-72 hr                                                      85° C./ (wt %) 0.36 0.37 0.36 0.35 0.36                                85%-168 hr                                                                 __________________________________________________________________________     *pbw: parts by weight                                                    

We claim:
 1. A process for producing a highly reactive modified phenolicresin in one step, which comprises mixing a petroleum heavy oil or pitchwith 0.3 to 10 mol of a phenol, 0.2 to 9 mol, in terms of formaldehyde,of a formaldehyde compound and 0.01 to 3.0 mol of an acid catalyst, eachamount being based on 1 mol of the petroleum heavy oil or pitchcalculated from an average molecular weight; andheating the resultingmixture with stirring, thereby to polycondensate the petroleum heavy oilor pitch, phenol and formaldehyde compound.
 2. The process for producinga highly reactive modified phenolic resin in one step according to claim1, wherein the phenol, formaldehyde compound and acid catalyst arerespectively used in the amount of 1 to 10 mol, 0.5 to 9 mol and 0.05 to3.0 mol, based on 1 mol of the petroleum heavy oil or pitch calculatedfrom the average molecular weight.
 3. A process for producing a highlyreactive modified phenolic resin, which comprises:mixing a heavy oil orpitch with a phenol, followed by heating them with stirring; and addinggradually an acid catalyst and 1 mol or less, in terms of formaldehyde,of a formaldehyde compound based on 1 mol of the phenol to the mixturewhile heating with stirring, thereby to polycondensate the heavy oil orpitch, phenol and formaldehyde compound.
 4. The process for producing ahighly reactive modified phenolic resin according to claim 3, wherein apart of the formaldehyde compound is previously added to the mixture andthe remainder is gradually added.
 5. A process for producing a highlyreactive modified phenolic resin, which comprises:mixing a heavy oil orpitch, a phenol and 1 mol or less, in terms of formaldehyde, of aformaldehyde compound based on 1 mol of the phenol, followed by heatingthem with stirring; and adding gradually an acid catalyst to the mixturewhile heating with stirring, thereby to polycondensate the heavy oil orpitch, phenol and formaldehyde compound.
 6. A process for producing ahighly reactive modified phenolic resin, which comprises:mixing a heavyoil or pitch, a phenol and an acid catalyst, followed by heating themwith stirring; and adding gradually 1 mol or less, in terms offormaldehyde, of a formaldehyde compound based on 1 mol of the phenol tothe mixture while heating with stirring, thereby to polycondensate theheavy oil or pitch, phenol and formaldehyde compound.
 7. A process forproducing a highly reactive modified phenolic resin, whichcomprises:mixing a heavy oil or pitch with an acid catalyst, followed byheating them with stirring; and adding gradually 1 mol or less, in termsof formaldehyde, of a formaldehyde compound based on 1 mol of thephenol, and phenol to the mixture while heating with stirring, therebyto polycondensate the heavy oil or pitch, phenol and formaldehydecompound.
 8. A process for producing a highly reactive modified phenolicresin, which comprises:mixing 1 mol or less, in terms of formaldehyde,of a formaldehyde compound based on 1 mol of a phenol with an acidcatalyst, followed by heating them with stirring; and adding gradually aheavy oil or pitch and the phenol to the mixture while heating withstirring, thereby to polycondensate the heavy oil or pitch, phenol andformaldehyde compound.
 9. A process for producing a highly reactivemodified phenolic resin in one step, which comprises mixing a coal-basedheavy oil or pitch with 0.3 to 4.6 mol of a phenol, 0.2 to 3.5 mol, interms of formaldehyde, of a formaldehyde compound and 0.01 to 3.0 mol ofan acid catalyst, each amount being based on 1 mol of the coal-basedheavy oil or pitch calculated from an average molecular weight;andheating the resulting mixture with stirring, thereby topolycondensate the coal-based heavy oil or pitch, phenol andformaldehyde compound.
 10. The process for producing a highly reactivemodified phenolic resin according to any one of claims 1 to 8 and 9,wherein the heavy oil or pitch is a petroleum heavy oil or pitch. 11.The process for producing a highly reactive modified phenolic resinaccording to any one of claims 1 to 8 and 9, wherein the heavy oil orpitch is a distilled oil which is obtained in a catalytic cracking stepor a thermal cracking step of a petroleum refining process and which hasa true boiling point of 180 to 500° C., an aromatic hydrocarbon fractionfa value of 0.40 to 0.95 and an aromatic ring hydrogen content Ha valueof 20 to 80%.
 12. The process for producing a highly reactive modifiedphenolic resin according to any one of claims 1 to 8 and 9, wherein anaromatic hydrocarbon compound is used as a raw material, in addition tothe heavy oil or pitch.
 13. The process for producing a highly reactivemodified phenolic resin according to any one of claims 1 to 8 and 9,wherein the acid catalyst is a Br.o slashed.nsted acid selected from thegroup consisting of organic acid, inorganic acid and solid acid.
 14. Theprocess for producing a highly reactive modified phenolic resinaccording to any one of claims 1 to 8 and 9, wherein the acid catalystis an acidic cation exchange resin.
 15. The method for producing ahighly reactive modified phenolic resin according to any one of claims 1to 8 and 9, wherein the heavy oil or pitch is used after subjecting to aparaffin fraction removing treatment.
 16. The process for producing ahighly reactive modified phenolic resin according to any one of claims 1to 8 and 9, wherein the highly reactive modified phenolic resin obtainedby the polycondensation reaction is purified by at least one stepselected from the group consisting of:(i) a step of removing anunreacted component from a reaction mixture by at least one treatmentselected from the group consisting of a treatment of bringing thereaction mixture containing the highly reactive modified phenolic resininto contact with an extraction solvent containing at least one compoundselected from the group consisting of an aliphatic hydrocarbon, analicyclic hydrocarbon and an aliphatic petroleum fraction at atemperature where the polycondensated reaction mixture becomes a flowstate; a treatment of diluting the reaction mixture containing thehighly reactive modified phenolic resin with a soluble solvent toprepare a solution and introducing the solution into a solventcontaining at least one compound selected from the group consisting ofan aliphatic hydrocarbon having 10 or less carbon atoms, an alicyclichydrocarbon having 10 or less carbon atoms and an aliphatic petroleumfraction; a treatment of diluting the reaction mixture with a solublesolvent to prepare a solution and bringing the resulting solution intocontact with an extraction solvent which forms a liquid-liquid two-layersolvent system with this solution containing the highly reactivemodified phenolic resin and can dissolve an unreacted component; atreatment of standing the reaction mixture in a heat-molten state andremoving the supernatant by decantation; a treatment of performingmolecular distillation of the reaction mixture under high vacuum of 10⁻⁷to 10⁻⁴ mmHg; and a treatment of diluting the reaction mixture with asoluble solvent to prepare a solution, mixing the resulting solutionwith water, standing to form a three-layer solvent system consisting ofa highly reactive modified phenolic resin solution layer, an aqueouslayer and an unreacted oil layer in order from the bottom and removingthe aqueous layer and unreacted oil layer; (ii) a step of removing acatalyst residue; and (iii) a step of removing the remained phenol byany one of steam distillation, blowing of a nitrogen gas and vacuumdistillation.